Add tooltips for meta keys to the weighting screen.

[JakePT]

Description of the Change

Adds a tooltip for field names for meta keys on the weighting screen to allow seeing the full name if it has been truncated.

Closes #3851

How to test the Change

1. On the weighting screen, add a field with a name longer than 30 characters, it should be truncated with an ellipsis (...).
2. Hover over the field name, the full meta key should be visible in a tooltop.

Changelog Entry

Added - A tooltip for meta keys to the weighting screen to allow seeing the full key if it has been truncated.

Credits

Props @JakePT

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.