Misc. security improvements

[Abrynos]

Checklist

• [x] I read and understood the Contributing Guidelines.
• [x] This is not a duplicate of an existing merge request.
• [x] I believe this falls into the scope of the project and should be part of the built-in functionality.
• [x] My code follows the code style of this project.
• [x] I have added tests to cover my changes, wherever they are necessary.
• [x] All new and existing tests pass.

Changes

New functionality

Added x-security-critical attribute to openapi schema.

Changed functionality

LicenseID property in global config is not serialized any more when requested via API due to security concerns raised on our community Discord server.

Removed functionality

None

Additional info

Thanks you for considering the inclusion of this merge request.

[JustArchi]

Thanks! :trophy: