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/utilities/scenexplain.py

@@ -0,0 +1,65 @@
+"""Util that calls SceneXplain.
+
+In order to set this up, you need API key for the SceneXplain API.
+You can obtain a key by following the steps below.
+- Sign up for a free account at https://scenex.jina.ai/.
+- Navigate to the API Access page (https://scenex.jina.ai/api) and create a new API key.
+"""
+from typing import Dict
+
+import requests
+from langchain_core.pydantic_v1 import BaseModel, BaseSettings, Field, root_validator
+from langchain_core.utils import get_from_dict_or_env
+
+
+class SceneXplainAPIWrapper(BaseSettings, BaseModel):
+    """Wrapper for SceneXplain API.
+
+    In order to set this up, you need API key for the SceneXplain API.
+    You can obtain a key by following the steps below.
+    - Sign up for a free account at https://scenex.jina.ai/.
+    - Navigate to the API Access page (https://scenex.jina.ai/api)
+      and create a new API key.
+    """
+
+    scenex_api_key: str = Field(..., env="SCENEX_API_KEY")
+    scenex_api_url: str = "https://api.scenex.jina.ai/v1/describe"
+
+    def _describe_image(self, image: str) -> str:
+        headers = {
+            "x-api-key": f"token {self.scenex_api_key}",
+            "content-type": "application/json",
+        }
+        payload = {
+            "data": [
+                {
+                    "image": image,
+                    "algorithm": "Ember",
+                    "languages": ["en"],
+                }
+            ]
+        }
+        response = requests.post(self.scenex_api_url, headers=headers, json=payload)
+        response.raise_for_status()
+        result = response.json().get("result", [])
+        img = result[0] if result else {}
+
+        return img.get("text", "")
+
+    @root_validator(pre=True)
+    def validate_environment(cls, values: Dict) -> Dict:
+        """Validate that api key exists in environment."""
+        scenex_api_key = get_from_dict_or_env(
+            values, "scenex_api_key", "SCENEX_API_KEY"
+        )
+        values["scenex_api_key"] = scenex_api_key
+
+        return values
+
+    def run(self, image: str) -> str:
+        """Run SceneXplain image explainer."""
+        description = self._describe_image(image)
+        if not description:
+            return "No description found."
+
+        return description