Add `Security status::not in advisory policy`

Problem/Motivation

Security issues can be filed in the drupalcode gitlab instance even if they are not in the scope of getting a security advisory. We need a status for those.

Additionally, it would be great to automatically add this label if a module does not match the policy.

Steps to reproduce

Have a confidential issue in gitlab that is not in the security advisory policy, but it's not easy to see that with a quick glance and the current "security status" values are not applicable.

Proposed resolution

Add a new status to the "security status" grouping called "not in advisory policy"

Remaining tasks

? Gitlab admin needs to do stuff?

User interface changes

yes.

API changes

n/a.

Data model changes

n/a.