Code dropdown: Migrate to GlDisclosureDropdown

app/assets/javascripts/pages/projects/show/index.js

app/assets/javascripts/repository/index.js

..._shared/components/clone_dropdown/clone_dropdown_item.vue

...pts/vue_shared/components/code_dropdown/code_dropdown.vue

app/views/projects/buttons/_code.html.haml

app/views/projects/empty.html.haml

ee/app/views/projects/buttons/_code.html.haml

...pec/features/projects/kerberos_clone_instructions_spec.rb

locale/gitlab.pot

qa/qa/page/component/clone_panel.rb

qa/qa/page/project/show.rb

...features/admin/admin_disables_git_access_protocol_spec.rb

spec/features/projects/show/clone_button_spec.rb

...features/projects/show/user_sees_git_instructions_spec.rb

...vue_shared/components/code_dropdown/code_dropdown_spec.js