Add customizable user roles (#18641)

* Add customizable user roles

* Various fixes and improvements

* Add migration for old settings and fix tootctl role management

app/lib/admin/system_check/base_check.rb

@@ -1,6 +1,16 @@
 # frozen_string_literal: true
 
 class Admin::SystemCheck::BaseCheck
+  attr_reader :current_user
+
+  def initialize(current_user)
+    @current_user = current_user
+  end
+
+  def skip?
+    false
+  end
+
   def pass?
     raise NotImplementedError
   end