Enable even more frozen string in app/controllers

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.

app/controllers/concerns/invalid_utf8_error_handler.rb

+# frozen_string_literal: true
+
 module InvalidUTF8ErrorHandler
   extend ActiveSupport::Concern

app/controllers/projects/application_controller.rb

+# frozen_string_literal: true
+
 class Projects::ApplicationController < ApplicationController
   include CookiesHelper
   include RoutableActions

app/controllers/projects/artifacts_controller.rb

+# frozen_string_literal: true
+
 class Projects::ArtifactsController < Projects::ApplicationController
   include ExtractsPath
   include RendersBlob

app/controllers/projects/autocomplete_sources_controller.rb

+# frozen_string_literal: true
+
 class Projects::AutocompleteSourcesController < Projects::ApplicationController
   before_action :load_autocomplete_service, except: [:members]

app/controllers/projects/avatars_controller.rb

+# frozen_string_literal: true
+
 class Projects::AvatarsController < Projects::ApplicationController
   include SendsBlob

app/controllers/projects/badges_controller.rb

+# frozen_string_literal: true
+
 class Projects::BadgesController < Projects::ApplicationController
   layout 'project_settings'
   before_action :authorize_admin_project!, only: [:index]

app/controllers/projects/blame_controller.rb

+# frozen_string_literal: true
+
 # Controller for viewing a file's blame
 class Projects::BlameController < Projects::ApplicationController
   include ExtractsPath

app/controllers/projects/blob_controller.rb

+# frozen_string_literal: true
+
 # Controller for viewing a file's blame
 class Projects::BlobController < Projects::ApplicationController
   include ExtractsPath

app/controllers/projects/boards_controller.rb

+# frozen_string_literal: true
+
 class Projects::BoardsController < Projects::ApplicationController
   include BoardsResponses
   include IssuableCollections

app/controllers/projects/branches_controller.rb

+# frozen_string_literal: true
+
 class Projects::BranchesController < Projects::ApplicationController
   include ActionView::Helpers::SanitizeHelper
   include SortingHelper

app/controllers/projects/build_artifacts_controller.rb

+# frozen_string_literal: true
+
 class Projects::BuildArtifactsController < Projects::ApplicationController
   include ExtractsPath
   include RendersBlob

app/controllers/projects/builds_controller.rb

+# frozen_string_literal: true
+
 class Projects::BuildsController < Projects::ApplicationController
   before_action :authorize_read_build!

app/controllers/projects/ci/lints_controller.rb

+# frozen_string_literal: true
+
 class Projects::Ci::LintsController < Projects::ApplicationController
   before_action :authorize_create_pipeline!

app/controllers/projects/clusters/applications_controller.rb

+# frozen_string_literal: true
+
 class Projects::Clusters::ApplicationsController < Projects::ApplicationController
   before_action :cluster
   before_action :application_class, only: [:create]

app/controllers/projects/clusters_controller.rb

+# frozen_string_literal: true
+
 class Projects::ClustersController < Projects::ApplicationController
   before_action :cluster, except: [:index, :new, :create_gcp, :create_user]
   before_action :authorize_read_cluster!

app/controllers/projects/commit_controller.rb

+# frozen_string_literal: true
+
 # Controller for a specific Commit
 #
 # Not to be confused with CommitsController, plural.

app/controllers/projects/commits_controller.rb

+# frozen_string_literal: true
+
 require "base64"
 class Projects::CommitsController < Projects::ApplicationController

app/controllers/projects/compare_controller.rb

+# frozen_string_literal: true
+
 require 'addressable/uri'
 class Projects::CompareController < Projects::ApplicationController

app/controllers/projects/cycle_analytics/events_controller.rb

+# frozen_string_literal: true
+
 module Projects
   module CycleAnalytics
     class EventsController < Projects::ApplicationController

app/controllers/projects/cycle_analytics_controller.rb

+# frozen_string_literal: true
+
 class Projects::CycleAnalyticsController < Projects::ApplicationController
   include ActionView::Helpers::DateHelper
   include ActionView::Helpers::TextHelper