community: Add new fields in metadata for qdrant vector store (#16608)

## Description

The PR is to return the ID and collection name from qdrant client to
metadata field in `Document` class.

## Issue

The motivation is almost same to
[11592](https://github.com/langchain-ai/langchain/issues/11592)

Returning ID is useful to update existing records in a vector store, but
we cannot know them if we use some retrievers.

In order to avoid any conflicts, breaking changes, the new fields in
metadata have a prefix `_`

## Dependencies

N/A

## Twitter handle

@kill_in_sun

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libs/community/langchain_community/vectorstores/qdrant.py

@@ -1941,9 +1941,12 @@ class Qdrant(VectorStore):
         content_payload_key: str,
         metadata_payload_key: str,
     ) -> Document:
+        metadata = scored_point.payload.get(metadata_payload_key) or {}
+        metadata["_id"] = scored_point.id
+        metadata["_collection_name"] = scored_point.collection_name
         return Document(
             page_content=scored_point.payload.get(content_payload_key),
-            metadata=scored_point.payload.get(metadata_payload_key) or {},
+            metadata=metadata,
         )
 
     def _build_condition(self, key: str, value: Any) -> List[rest.FieldCondition]: