Add documents and embbedings database metrics to IndexStats

[Alirexaa]

Pull Request

Related issue

Fixes #629
Fixes #628

What does this PR do?

This pull request includes changes to the IndexStats class in the Meilisearch namespace to enhance its functionality by adding new properties. These changes aim to provide more detailed statistics about the indexed documents.

Enhancements to IndexStats class:

• src/Meilisearch/IndexStats.cs: Added new properties RawDocumentDbSize, AvgDocumentSize, NumberOfEmbeddedDocuments, and NumberOfEmbeddings to the IndexStats class. These properties provide additional insights into the size and structure of the indexed documents. [1] [2]

PR checklist

Please check if your PR fulfills the following requirements:

• Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
• Have you read the contributing guidelines?
• Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!

[brunoocasali]

LGTM! bors merge

[curquiza]

bors merge

[meili-bors]

Build succeeded:

• integration-tests
• format-check