Database column changes to rename Secret Push Protection - M+1

Overview

Related to #511969 (closed)

Since we are renaming pre-receive secret detection to secret push protection, we should update the code to reflect this. This includes renaming columns, policy checks, and other places. Issue #511969 (closed) addresses the "release M" steps for renaming a database column. This issue addresses the M+1 steps, which is "Remove the ignore rule".

Follow the database migration steps to rename the columns. In 17.9 we will complete the "release M" steps, which are 1. Add the regular migration, 2. Ignore the column, and 3. Add a post-deployment migration. In 17.10, we will complete the "release M+1" step, which is Remove the ignore rule.

Considerations

We may need to double check how this affects the metric definition added in !156076 (merged).