Add customizable user roles (#18641)

* Add customizable user roles

* Various fixes and improvements

* Add migration for old settings and fix tootctl role management

db/post_migrate/20220704024901_migrate_settings_to_user_roles.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class MigrateSettingsToUserRoles < ActiveRecord::Migration[6.1]
+  disable_ddl_transaction!
+
+  class UserRole < ApplicationRecord; end
+
+  def up
+    owner_role     = UserRole.find_by(name: 'Owner')
+    admin_role     = UserRole.find_by(name: 'Admin')
+    moderator_role = UserRole.find_by(name: 'Moderator')
+    everyone_role  = UserRole.find_by(id: -99)
+
+    min_invite_role  = Setting.min_invite_role
+    show_staff_badge = Setting.show_staff_badge
+
+    if everyone_role
+      everyone_role.permissions &= ~::UserRole::FLAGS[:invite_users] unless min_invite_role == 'user'
+      everyone_role.save
+    end
+
+    if owner_role
+      owner_role.highlighted = show_staff_badge
+      owner_role.save
+    end
+
+    if admin_role
+      admin_role.permissions |= ::UserRole::FLAGS[:invite_users] if %w(admin moderator).include?(min_invite_role)
+      admin_role.highlighted  = show_staff_badge
+      admin_role.save
+    end
+
+    if moderator_role
+      moderator_role.permissions |= ::UserRole::FLAGS[:invite_users] if %w(moderator).include?(min_invite_role)
+      moderator_role.highlighted  = show_staff_badge
+      moderator_role.save
+    end
+  end
+
+  def down; end
+end