add config choice for milvus database name

[DStarEpoch]

Description

Add database name choice configuration options to milvus to facilitate isolation of memory storage for different projects

Type of change

• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules
• [x] I have checked my code and corrected any misspellings

Maintainer Checklist

• [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
• [x] Made sure Checks passed

[CLAassistant]

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1 out of 2 committers have signed the CLA.

:white_check_mark: DStarEpoch
:x: yeqing

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[parshvadaftari]

@DStarEpoch We have already added this!