[Databricks] Update in code and docs to expect and show correct column names, also update in vector search logic

[rahul-anand1]

Description

Changes:

1. Updated docs to correctly show the information which is expected by the code. Also updated the schema name to avoid any confusions from users.
2. Updated the logic in vector search methods get and list. Since they both were only catering the needs of text based search, added condition to check if text based search is required or vector based search.

Type of change

Please delete options that are not relevant.

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

This change is been tested by integrating databricks in a mem0 application using databricks and memories are being stored and retrieved as expected.

• Unit Test

Checklist:

• My code follows the style guidelines of this project
• 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
• 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
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• closes Issue in docs related to supported vector databases in databricks section #3638
• Made sure Checks passed

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