chore: Refactor Contact Inbox Builders (#5617)

- Remove duplicate code and move everything to builders
- fixes: #4680

app/controllers/api/v1/accounts/contacts_controller.rb

@@ -134,8 +134,11 @@ class Api::V1::Accounts::ContactsController < Api::V1::Accounts::BaseController
     return if params[:inbox_id].blank?
 
     inbox = Current.account.inboxes.find(params[:inbox_id])
-    source_id = params[:source_id] || SecureRandom.uuid
-    ContactInbox.create!(contact: @contact, inbox: inbox, source_id: source_id)
+    ContactInboxBuilder.new(
+      contact: @contact,
+      inbox: inbox,
+      source_id: params[:source_id]
+    ).perform
   end
 
   def permitted_params