Allow user to provide customized collection_name

[AICrafterZheng]

Description

The collection name is constructed with f"{container_name}-{embedding_name}".replace(".", "-")
But embedding_name is picked from one of:
https://github.com/microsoft/graphrag/blob/1da138061501aa4f8065d2e8783193e2cbe920b1/graphrag/config/embeddings.py#L6C1-L14C1

So for text_unit_text_embedding scenario, a collection name like test_text_unit_text will be generated (test is the container_name from config yaml). But in some cases, a user needs a full customized name e.g. test.

Related Issues

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Proposed Changes

Don't generated the collection_name if users provide one.

Checklist

• I have tested these changes locally.
• I have reviewed the code changes.
• I have updated the documentation (if necessary).
• [] I have added appropriate unit tests (if applicable).

Additional Notes

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