Transition Vulnerability Feedback to gitlab_sec database schema

it has been decided to remove the dependence on the vulnerability feedback table ahead of the sec decomposition as the table has not been in use for a long time.

This will not fully remove all traces of the feedback code, but remove any code that still interacts with it on a model level, dropping relationships and columns as needed to facilitate removal rather than decompose it.

Sadly, in attempting to remove vulnerability it was realised that this removal is far more complicated that immediate appearances might suggest. The work is substantial and will require a dedicated epic to conduct. We will have to transition the table to the new DB.

Implementation Plan

• Set application record to the new sec application record
• Break foreign keys into loose foreign keys
• Set gitlab_schema to gitlab_sec