feat: Unify user and super admin credentials (#3830)

Fixes: #3061, #3489

config/initializers/rack_attack.rb

@@ -72,6 +72,15 @@ class Rack::Attack
     end
   end
 
+  throttle('super_admin_login/email', limit: 20, period: 5.minutes) do |req|
+    if req.path == '/super_admin/sign_in' && req.post?
+      # NOTE: This line used to throw ArgumentError /rails/action_mailbox/sendgrid/inbound_emails : invalid byte sequence in UTF-8
+      # Hence placed in the if block
+      email = req.params['email'].presence || ActionDispatch::Request.new(req.env).params['email'].presence
+      email.to_s.downcase.gsub(/\s+/, '')
+    end
+  end
+
   throttle('reset_password/email', limit: 5, period: 1.hour) do |req|
     if req.path == '/auth/password' && req.post?
       email = req.params['email'].presence || ActionDispatch::Request.new(req.env).params['email'].presence

config/routes.rb

@@ -303,7 +303,6 @@ Rails.application.routes.draw do
       # order of resources affect the order of sidebar navigation in super admin
       resources :accounts
       resources :users, only: [:index, :new, :create, :show, :edit, :update]
-      resources :super_admins
       resources :access_tokens, only: [:index, :show]
       resources :installation_configs, only: [:index, :new, :create, :show, :edit, :update]