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

spec/fabricators/account_warning_fabricator.rb

@@ -1,5 +1,6 @@
 Fabricator(:account_warning) do
-  account        nil
-  target_account nil
-  text           "MyText"
+  account
+  target_account(fabricator: :account)
+  text { Faker::Lorem.paragraph }
+  action 'suspend'
 end

spec/fabricators/appeal_fabricator.rb

@@ -0,0 +1,5 @@
+Fabricator(:appeal) do
+  strike(fabricator: :account_warning)
+  account { |attrs| attrs[:strike].target_account }
+  text { Faker::Lorem.paragraph }
+end