Enables frozen string for the following:

* lib/gitlab/patch/**/*.rb
* lib/gitlab/popen/**/*.rb
* lib/gitlab/profiler/**/*.rb
* lib/gitlab/project_authorizations/**/*.rb
* lib/gitlab/prometheus/**/*.rb
* lib/gitlab/query_limiting/**/*.rb
* lib/gitlab/quick_actions/**/*.rb
* lib/gitlab/redis/**/*.rb
* lib/gitlab/request_profiler/**/*.rb
* lib/gitlab/search/**/*.rb
* lib/gitlab/sherlock/**/*.rb
* lib/gitlab/sidekiq_middleware/**/*.rb
* lib/gitlab/slash_commands/**/*.rb
* lib/gitlab/sql/**/*.rb
* lib/gitlab/template/**/*.rb
* lib/gitlab/testing/**/*.rb
* lib/gitlab/utils/**/*.rb
* lib/gitlab/webpack/**/*.rb

Partially addresses gitlab-org/gitlab-ce#47424.

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

Eliminates "warning: already initialized constant Gitlab::Sanitizers::SVG::ALLOWED_ELEMENTS"

Use a custom Loofah scrubber since sanitize 2.x transformers are inadequate
to handle case-sensitive SVG attributes. sanitize parses documents as HTML
instead of XML, which causes all SVG attribute names (e.g. viewBox) to be downcased.

* SVG element list: https://www.w3.org/TR/SVG/eltindex.html
* SVG attribute list: https://www.w3.org/TR/SVG/attindex.html

Closes #14555