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/embeddings/huggingface_hub.py

@@ -0,0 +1,109 @@
+import json
+from typing import Any, Dict, List, Optional
+
+from langchain_core.embeddings import Embeddings
+from langchain_core.pydantic_v1 import BaseModel, Extra, root_validator
+from langchain_core.utils import get_from_dict_or_env
+
+DEFAULT_MODEL = "sentence-transformers/all-mpnet-base-v2"
+VALID_TASKS = ("feature-extraction",)
+
+
+class HuggingFaceHubEmbeddings(BaseModel, Embeddings):
+    """HuggingFaceHub embedding models.
+
+    To use, you should have the ``huggingface_hub`` python package installed, and the
+    environment variable ``HUGGINGFACEHUB_API_TOKEN`` set with your API token, or pass
+    it as a named parameter to the constructor.
+
+    Example:
+        .. code-block:: python
+
+            from langchain_community.embeddings import HuggingFaceHubEmbeddings
+            model = "sentence-transformers/all-mpnet-base-v2"
+            hf = HuggingFaceHubEmbeddings(
+                model=model,
+                task="feature-extraction",
+                huggingfacehub_api_token="my-api-key",
+            )
+    """
+
+    client: Any  #: :meta private:
+    model: Optional[str] = None
+    """Model name to use."""
+    repo_id: Optional[str] = None
+    """Huggingfacehub repository id, for backward compatibility."""
+    task: Optional[str] = "feature-extraction"
+    """Task to call the model with."""
+    model_kwargs: Optional[dict] = None
+    """Keyword arguments to pass to the model."""
+
+    huggingfacehub_api_token: Optional[str] = None
+
+    class Config:
+        """Configuration for this pydantic object."""
+
+        extra = Extra.forbid
+
+    @root_validator()
+    def validate_environment(cls, values: Dict) -> Dict:
+        """Validate that api key and python package exists in environment."""
+        huggingfacehub_api_token = get_from_dict_or_env(
+            values, "huggingfacehub_api_token", "HUGGINGFACEHUB_API_TOKEN"
+        )
+        try:
+            from huggingface_hub import InferenceClient
+
+            if values["model"]:
+                values["repo_id"] = values["model"]
+            elif values["repo_id"]:
+                values["model"] = values["repo_id"]
+            else:
+                values["model"] = DEFAULT_MODEL
+                values["repo_id"] = DEFAULT_MODEL
+
+            client = InferenceClient(
+                model=values["model"],
+                token=huggingfacehub_api_token,
+            )
+            if values["task"] not in VALID_TASKS:
+                raise ValueError(
+                    f"Got invalid task {values['task']}, "
+                    f"currently only {VALID_TASKS} are supported"
+                )
+            values["client"] = client
+        except ImportError:
+            raise ImportError(
+                "Could not import huggingface_hub python package. "
+                "Please install it with `pip install huggingface_hub`."
+            )
+        return values
+
+    def embed_documents(self, texts: List[str]) -> List[List[float]]:
+        """Call out to HuggingFaceHub's embedding endpoint for embedding search docs.
+
+        Args:
+            texts: The list of texts to embed.
+
+        Returns:
+            List of embeddings, one for each text.
+        """
+        # replace newlines, which can negatively affect performance.
+        texts = [text.replace("\n", " ") for text in texts]
+        _model_kwargs = self.model_kwargs or {}
+        responses = self.client.post(
+            json={"inputs": texts, "parameters": _model_kwargs, "task": self.task}
+        )
+        return json.loads(responses.decode())
+
+    def embed_query(self, text: str) -> List[float]:
+        """Call out to HuggingFaceHub's embedding endpoint for embedding query text.
+
+        Args:
+            text: The text to embed.
+
+        Returns:
+            Embeddings for the text.
+        """
+        response = self.embed_documents([text])[0]
+        return response