GRN2-176: Create a role editor that allows admins to specify what permissions each role has (#709)

* Add roles editor

* Add colour selection ability to roles

* Add ability to assign roles to users in the UI

* Remove rolify and replace it with our own custom roles implemenation

* - Fix all existing roles functionality
- Fix super admins

* Fix bugs with new customers not have default roles

* Add can't create room setting

* Code improvements

* Fix migration

* Add tests for new methods

* Translate reserved role names

* Pull roles from saml/ldap

* Fix rspec

* Fix scrutinizer issues

* Fix email promoted/demoted tests

* Apply comments

* Redirect directly to the main room

* Add comments

app/controllers/concerns/emailer.rb

@@ -35,16 +35,16 @@ module Emailer
     UserMailer.password_reset(@user, reset_link, logo_image, user_color).deliver_now
   end
 
-  def send_user_promoted_email(user)
+  def send_user_promoted_email(user, role)
     return unless Rails.configuration.enable_email_verification
 
-    UserMailer.user_promoted(user, root_url, logo_image, user_color).deliver_now
+    UserMailer.user_promoted(user, role, root_url, logo_image, user_color).deliver_now
   end
 
-  def send_user_demoted_email(user)
+  def send_user_demoted_email(user, role)
     return unless Rails.configuration.enable_email_verification
 
-    UserMailer.user_demoted(user, root_url, logo_image, user_color).deliver_now
+    UserMailer.user_demoted(user, role, root_url, logo_image, user_color).deliver_now
   end
 
   # Sends inivitation to join
@@ -87,7 +87,7 @@ module Emailer
   end
 
   def admin_emails
-    admins = User.with_role(:admin)
+    admins = User.all_users_with_roles.where(roles: { can_manage_users: true })
 
     if Rails.configuration.loadbalanced_configuration
       admins = admins.without_role(:super_admin)