Add knowledge base evaluation functionality

[dusvyat]

Description

Introduced methods for evaluating knowledge bases using test queries, calculating metrics, and storing results in the database. Added API endpoints to trigger evaluation, fetch evaluation history, and retrieve specific evaluation details. Includes unit tests for validating evaluation logic and metric calculations.

Fixes #issue_number

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)
• [ ] 📢 Breaking change (fix or feature that would cause existing functionality not to work as expected)
• [ ] 📄 This change requires a documentation update

Verification Process

To ensure the changes are working as expected:

• [ ] Test Location: Specify the URL or path for testing.
• [ ] 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.