feat: add job to remove stale contacts and contact_inboxes (#11186)

- Add a job to remove stale contacts and contact_inboxes across all accounts

Stale anonymous contact is defined as 
- have no identification (email, phone_number, and identifier are NULL)
- have no conversations
- are older than 30 days

---------

Co-authored-by: Pranav <pranav@chatwoot.com>
Co-authored-by: Shivam Mishra <scm.mymail@gmail.com>

app/jobs/internal/process_stale_contacts_job.rb

@@ -0,0 +1,18 @@
+# housekeeping
+# remove stale contacts for all accounts
+# - have no identification (email, phone_number, and identifier are NULL)
+# - have no conversations
+# - are older than 30 days
+
+class Internal::ProcessStaleContactsJob < ApplicationJob
+  queue_as :scheduled_jobs
+
+  def perform
+    Account.find_in_batches(batch_size: 100) do |accounts|
+      accounts.each do |account|
+        Rails.logger.info "Enqueuing RemoveStaleContactsJob for account #{account.id}"
+        Internal::RemoveStaleContactsJob.perform_later(account)
+      end
+    end
+  end
+end

app/jobs/internal/remove_stale_contacts_job.rb

@@ -0,0 +1,13 @@
+# housekeeping
+# remove contacts that:
+# - have no identification (email, phone_number, and identifier are NULL)
+# - have no conversations
+# - are older than 30 days
+
+class Internal::RemoveStaleContactsJob < ApplicationJob
+  queue_as :low
+
+  def perform(account, batch_size = 1000)
+    Internal::RemoveStaleContactsService.new(account: account).perform(batch_size)
+  end
+end