Update Astra DB integration for API changes

[erichare]

Description

This adds metadata filtering and MMR query mode support for the Astra DB integration. It also updates the existing integration to support a change to the server-side Astra JSON API.

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• I stared at the code and made sure it makes sense

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added Google Colab support for the newly added notebooks.
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I ran make format; make lint to appease the lint gods

[erichare]

@nerdai We have another Astra DB update - this extends some of the functionality of the integration and fixes one issue with respect to an API update on the Astra DB server. Thanks so much.

[nerdai]

looks really great -- thanks!!!