Add Retries & Fallback to SQL Retriever

[tmichaeldb]

Description

LLMs will not always generate correct SQL queries to be used with pgvector for hybrid search. In this case, we should try to correct the query n times, and then fallback to our default retriever if executing the corrected queries still return errors.

This way, worst case, we just use our default retriever without metadata instead of returning an error.

Related to ML-240

Type of change

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

Verification Process

To ensure the changes are working as expected:

• Test Location: ./tests/unit/test_sql_retriever.py
• 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.

Additional Media:

• I have attached a brief loom video or screenshots showcasing the new functionality or change.

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.

[dusvyat]

nice one, lgtm

[QuantumPlumber]

Had a look, LGTM