chore: Custom Roles to manage permissions [ UI ] (#9865)

In admin settings, this Pr will add the UI for managing custom roles (
ref: https://github.com/chatwoot/chatwoot/pull/9995 ). It also handles
the routing logic changes to accommodate fine-tuned permissions.

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/policies/article_policy.rb

@@ -33,3 +33,5 @@ class ArticlePolicy < ApplicationPolicy
     @record.first.portal.members.include?(@user)
   end
 end
+
+ArticlePolicy.prepend_mod_with('Enterprise::ArticlePolicy')