[BUG]: Increase Param Value String Length to 6000 to Match MLFlow Client

[vinayan3]

Describe the bug

The ML FLow SDK states the following for log_param method

value – Parameter value, but will be string-ified if not. All built-in backend stores support values up to length 6000, but some may support larger values.

The database backend only supports up to 500. See https://github.com/G-Research/fasttrackml/blob/main/pkg/database/model.go#L134

Environment

• FastTrackML Version: v0.6.0
• Operating System: All
• Database: SQLite & Postgres
• Artifact Storage: N/A

Steps To Reproduce

The python example can be ran and with this param

    mlflow.log_param("param1", "a"*1000)

Expected Behavior

The param should be logged

Additional Context (Optional)

No response