community[major], core[patch], langchain[patch], experimental[patch]: Create langchain-community (#14463)

Moved the following modules to new package langchain-community in a backwards compatible fashion:

```
mv langchain/langchain/adapters community/langchain_community
mv langchain/langchain/callbacks community/langchain_community/callbacks
mv langchain/langchain/chat_loaders community/langchain_community
mv langchain/langchain/chat_models community/langchain_community
mv langchain/langchain/document_loaders community/langchain_community
mv langchain/langchain/docstore community/langchain_community
mv langchain/langchain/document_transformers community/langchain_community
mv langchain/langchain/embeddings community/langchain_community
mv langchain/langchain/graphs community/langchain_community
mv langchain/langchain/llms community/langchain_community
mv langchain/langchain/memory/chat_message_histories community/langchain_community
mv langchain/langchain/retrievers community/langchain_community
mv langchain/langchain/storage community/langchain_community
mv langchain/langchain/tools community/langchain_community
mv langchain/langchain/utilities community/langchain_community
mv langchain/langchain/vectorstores community/langchain_community
mv langchain/langchain/agents/agent_toolkits community/langchain_community
mv langchain/langchain/cache.py community/langchain_community
mv langchain/langchain/adapters community/langchain_community
mv langchain/langchain/callbacks community/langchain_community/callbacks
mv langchain/langchain/chat_loaders community/langchain_community
mv langchain/langchain/chat_models community/langchain_community
mv langchain/langchain/document_loaders community/langchain_community
mv langchain/langchain/docstore community/langchain_community
mv langchain/langchain/document_transformers community/langchain_community
mv langchain/langchain/embeddings community/langchain_community
mv langchain/langchain/graphs community/langchain_community
mv langchain/langchain/llms community/langchain_community
mv langchain/langchain/memory/chat_message_histories community/langchain_community
mv langchain/langchain/retrievers community/langchain_community
mv langchain/langchain/storage community/langchain_community
mv langchain/langchain/tools community/langchain_community
mv langchain/langchain/utilities community/langchain_community
mv langchain/langchain/vectorstores community/langchain_community
mv langchain/langchain/agents/agent_toolkits community/langchain_community
mv langchain/langchain/cache.py community/langchain_community
```

Moved the following to core
```
mv langchain/langchain/utils/json_schema.py core/langchain_core/utils
mv langchain/langchain/utils/html.py core/langchain_core/utils
mv langchain/langchain/utils/strings.py core/langchain_core/utils
cat langchain/langchain/utils/env.py >> core/langchain_core/utils/env.py
rm langchain/langchain/utils/env.py
```

See .scripts/community_split/script_integrations.sh for all changes

libs/community/langchain_community/tools/gmail/utils.py

@@ -0,0 +1,132 @@
+"""Gmail tool utils."""
+from __future__ import annotations
+
+import logging
+import os
+from typing import TYPE_CHECKING, List, Optional, Tuple
+
+if TYPE_CHECKING:
+    from google.auth.transport.requests import Request
+    from google.oauth2.credentials import Credentials
+    from google_auth_oauthlib.flow import InstalledAppFlow
+    from googleapiclient.discovery import Resource
+    from googleapiclient.discovery import build as build_resource
+
+logger = logging.getLogger(__name__)
+
+
+def import_google() -> Tuple[Request, Credentials]:
+    """Import google libraries.
+
+    Returns:
+        Tuple[Request, Credentials]: Request and Credentials classes.
+    """
+    # google-auth-httplib2
+    try:
+        from google.auth.transport.requests import Request  # noqa: F401
+        from google.oauth2.credentials import Credentials  # noqa: F401
+    except ImportError:
+        raise ImportError(
+            "You need to install google-auth-httplib2 to use this toolkit. "
+            "Try running pip install --upgrade google-auth-httplib2"
+        )
+    return Request, Credentials
+
+
+def import_installed_app_flow() -> InstalledAppFlow:
+    """Import InstalledAppFlow class.
+
+    Returns:
+        InstalledAppFlow: InstalledAppFlow class.
+    """
+    try:
+        from google_auth_oauthlib.flow import InstalledAppFlow
+    except ImportError:
+        raise ImportError(
+            "You need to install google-auth-oauthlib to use this toolkit. "
+            "Try running pip install --upgrade google-auth-oauthlib"
+        )
+    return InstalledAppFlow
+
+
+def import_googleapiclient_resource_builder() -> build_resource:
+    """Import googleapiclient.discovery.build function.
+
+    Returns:
+        build_resource: googleapiclient.discovery.build function.
+    """
+    try:
+        from googleapiclient.discovery import build
+    except ImportError:
+        raise ImportError(
+            "You need to install googleapiclient to use this toolkit. "
+            "Try running pip install --upgrade google-api-python-client"
+        )
+    return build
+
+
+DEFAULT_SCOPES = ["https://mail.google.com/"]
+DEFAULT_CREDS_TOKEN_FILE = "token.json"
+DEFAULT_CLIENT_SECRETS_FILE = "credentials.json"
+
+
+def get_gmail_credentials(
+    token_file: Optional[str] = None,
+    client_secrets_file: Optional[str] = None,
+    scopes: Optional[List[str]] = None,
+) -> Credentials:
+    """Get credentials."""
+    # From https://developers.google.com/gmail/api/quickstart/python
+    Request, Credentials = import_google()
+    InstalledAppFlow = import_installed_app_flow()
+    creds = None
+    scopes = scopes or DEFAULT_SCOPES
+    token_file = token_file or DEFAULT_CREDS_TOKEN_FILE
+    client_secrets_file = client_secrets_file or DEFAULT_CLIENT_SECRETS_FILE
+    # The file token.json stores the user's access and refresh tokens, and is
+    # created automatically when the authorization flow completes for the first
+    # time.
+    if os.path.exists(token_file):
+        creds = Credentials.from_authorized_user_file(token_file, scopes)
+    # If there are no (valid) credentials available, let the user log in.
+    if not creds or not creds.valid:
+        if creds and creds.expired and creds.refresh_token:
+            creds.refresh(Request())
+        else:
+            # https://developers.google.com/gmail/api/quickstart/python#authorize_credentials_for_a_desktop_application # noqa
+            flow = InstalledAppFlow.from_client_secrets_file(
+                client_secrets_file, scopes
+            )
+            creds = flow.run_local_server(port=0)
+        # Save the credentials for the next run
+        with open(token_file, "w") as token:
+            token.write(creds.to_json())
+    return creds
+
+
+def build_resource_service(
+    credentials: Optional[Credentials] = None,
+    service_name: str = "gmail",
+    service_version: str = "v1",
+) -> Resource:
+    """Build a Gmail service."""
+    credentials = credentials or get_gmail_credentials()
+    builder = import_googleapiclient_resource_builder()
+    return builder(service_name, service_version, credentials=credentials)
+
+
+def clean_email_body(body: str) -> str:
+    """Clean email body."""
+    try:
+        from bs4 import BeautifulSoup
+
+        try:
+            soup = BeautifulSoup(str(body), "html.parser")
+            body = soup.get_text()
+            return str(body)
+        except Exception as e:
+            logger.error(e)
+            return str(body)
+    except ImportError:
+        logger.warning("BeautifulSoup not installed. Skipping cleaning.")
+        return str(body)