Add appeals (#17364)

* Add appeals

* Add ability to reject appeals and ability to browse pending appeals in admin UI

* Add strikes to account page in settings

* Various fixes and improvements

- Add separate notification setting for appeals, separate from reports
- Fix style of links in report/strike header
- Change approving an appeal to not restore statuses (due to federation complexities)
- Change style of successfully appealed strikes on account settings page
- Change account settings page to only show unappealed or recently appealed strikes

* Change appealed_at to overruled_at

* Fix missing method error

app/views/user_mailer/warning.html.haml

@@ -77,8 +77,8 @@
                             %tbody
                               %tr
                                 %td.button-primary
-                                  = link_to about_more_url do
-                                    %span= t 'user_mailer.warning.review_server_policies'
+                                  = link_to disputes_strike_url(@warning) do
+                                    %span= t 'user_mailer.warning.appeal'
 
 %table.email-table{ cellspacing: 0, cellpadding: 0 }
   %tbody
@@ -95,4 +95,4 @@
                         %tbody
                           %tr
                             %td.column-cell.text-center
-                              %p= t 'user_mailer.warning.get_in_touch', instance: @instance
+                              %p= t 'user_mailer.warning.appeal_description', instance: @instance