Langchain handler modifications

[abhayasr]

Description

-Stores the input and output of the llm in langchain_handler.py
-Use sqlite to be able to store both the input and the output of each query
-Added logs for when self improvement functionality works

Fixes #issue_number

Type of change

(Please delete options that are not relevant)

• ⚡ New feature (non-breaking change which adds functionality)

Verification Process

To ensure the changes are working as expected:

• Verification Steps: Outline the steps or queries needed to validate the change. Include any data, configurations, or actions required to reproduce or see the new functionality.

Checklist:

• My code follows the style guidelines(PEP 8) of MindsDB.
• I have appropriately commented on my code, especially in complex areas.
• Necessary documentation updates are either made or tracked in issues.
• Relevant unit and integration tests are updated or added.

[abhayasr]

@paxcema @TylerSandman

[paxcema]

This should probably be removed.

[abhayasr]

I don't know why this file is there, I don't think I added it, I think it was so I was able to launch the web version, next time I will git add specific files I did git add .

[paxcema]

Ah interesting. Well, you can remove specific files like this one with git rm /path/to/file