Add submit button to the top of preferences pages (#13068)

* Move submit button to the top of the edit page

* Duplicate save button on long form

* Fix click submit on profile spec

app/views/admin/settings/edit.html.haml

@@ -4,7 +4,10 @@
 - content_for :page_title do
   = t('admin.settings.title')
 
-= simple_form_for @admin_settings, url: admin_settings_path, html: { method: :patch } do |f|
+  - content_for :heading_actions do
+    = button_tag t('generic.save_changes'), class: 'button', form: 'edit_admin'
+
+= simple_form_for @admin_settings, url: admin_settings_path, html: { method: :patch, id: 'edit_admin' } do |f|
   = render 'shared/error_messages', object: @admin_settings
 
   .fields-group