- concerns
- dashboard
- groups
- import

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.

Adds a rubocop rule (with autocorrect) to ensure line break after guard clauses.

Add a rubocop rule to check if a method 'redirect_to' is used without explicitly set 'status' in 'destroy' actions of controllers

Reverted the change from the "expires_at" to "expires_at_groups" in the groups controller

Signed-off-by: Rémy Coutable <remy@rymai.me>

Closes #15330

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>