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

db/migrate/20220124141035_create_appeals.rb

@@ -0,0 +1,14 @@
+class CreateAppeals < ActiveRecord::Migration[6.1]
+  def change
+    create_table :appeals do |t|
+      t.belongs_to :account, null: false, foreign_key: { on_delete: :cascade }
+      t.belongs_to :account_warning, null: false, foreign_key: { on_delete: :cascade }, index: { unique: true }
+      t.text :text, null: false, default: ''
+      t.datetime :approved_at
+      t.belongs_to :approved_by_account, foreign_key: { to_table: :accounts, on_delete: :nullify }
+      t.datetime :rejected_at
+      t.belongs_to :rejected_by_account, foreign_key: { to_table: :accounts, on_delete: :nullify }
+      t.timestamps
+    end
+  end
+end

db/migrate/20220210153119_add_overruled_at_to_account_warnings.rb

@@ -0,0 +1,5 @@
+class AddOverruledAtToAccountWarnings < ActiveRecord::Migration[6.1]
+  def change
+    add_column :account_warnings, :overruled_at, :datetime
+  end
+end