Enables frozen string for some vestigial files as
well as the following:
* app/controllers/projects/**/*.rb
* app/controllers/sherlock/**/*.rb
* app/controllers/snippets/**/*.rb
* app/controllers/users/**/*.rb
Partially addresses #47424.
Improvements and refactorings were made while adding role based permissions for protected tags to EE. This doesn’t backport the feature, but should improve code quality and minimize divergence.
