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/document_loaders/apify_dataset.py

@@ -0,0 +1,77 @@
+from typing import Any, Callable, Dict, List
+
+from langchain_core.documents import Document
+from langchain_core.pydantic_v1 import BaseModel, root_validator
+
+from langchain_community.document_loaders.base import BaseLoader
+
+
+class ApifyDatasetLoader(BaseLoader, BaseModel):
+    """Load datasets from `Apify` web scraping, crawling, and data extraction platform.
+
+    For details, see https://docs.apify.com/platform/integrations/langchain
+
+    Example:
+        .. code-block:: python
+
+            from langchain_community.document_loaders import ApifyDatasetLoader
+            from langchain_core.documents import Document
+
+            loader = ApifyDatasetLoader(
+                dataset_id="YOUR-DATASET-ID",
+                dataset_mapping_function=lambda dataset_item: Document(
+                    page_content=dataset_item["text"], metadata={"source": dataset_item["url"]}
+                ),
+            )
+            documents = loader.load()
+    """  # noqa: E501
+
+    apify_client: Any
+    """An instance of the ApifyClient class from the apify-client Python package."""
+    dataset_id: str
+    """The ID of the dataset on the Apify platform."""
+    dataset_mapping_function: Callable[[Dict], Document]
+    """A custom function that takes a single dictionary (an Apify dataset item)
+     and converts it to an instance of the Document class."""
+
+    def __init__(
+        self, dataset_id: str, dataset_mapping_function: Callable[[Dict], Document]
+    ):
+        """Initialize the loader with an Apify dataset ID and a mapping function.
+
+        Args:
+            dataset_id (str): The ID of the dataset on the Apify platform.
+            dataset_mapping_function (Callable): A function that takes a single
+                dictionary (an Apify dataset item) and converts it to an instance
+                of the Document class.
+        """
+        super().__init__(
+            dataset_id=dataset_id, dataset_mapping_function=dataset_mapping_function
+        )
+
+    @root_validator()
+    def validate_environment(cls, values: Dict) -> Dict:
+        """Validate environment.
+
+        Args:
+            values: The values to validate.
+        """
+
+        try:
+            from apify_client import ApifyClient
+
+            values["apify_client"] = ApifyClient()
+        except ImportError:
+            raise ImportError(
+                "Could not import apify-client Python package. "
+                "Please install it with `pip install apify-client`."
+            )
+
+        return values
+
+    def load(self) -> List[Document]:
+        """Load documents."""
+        dataset_items = (
+            self.apify_client.dataset(self.dataset_id).list_items(clean=True).items
+        )
+        return list(map(self.dataset_mapping_function, dataset_items))