feat: Added the backend support for twilio content templates (#12272)

Added comprehensive Twilio WhatsApp content template support (Phase 1)
enabling text, media, and quick reply templates with proper parameter
conversion, sync capabilities.

 **Template Types Supported**
  - Basic Text Templates: Simple text with variables ({{1}}, {{2}})
  - Media Templates: Image/Video/Document templates with text variables
  - Quick Reply Templates: Interactive button templates
  
 Front end changes is available via #12277

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>

spec/jobs/channels/twilio/templates_sync_job_spec.rb

@@ -0,0 +1,50 @@
+require 'rails_helper'
+
+RSpec.describe Channels::Twilio::TemplatesSyncJob do
+  let!(:account) { create(:account) }
+  let!(:twilio_channel) { create(:channel_twilio_sms, medium: :whatsapp, account: account) }
+
+  it 'enqueues the job' do
+    expect { described_class.perform_later(twilio_channel) }.to have_enqueued_job(described_class)
+      .on_queue('low')
+      .with(twilio_channel)
+  end
+
+  describe '#perform' do
+    let(:template_sync_service) { instance_double(Twilio::TemplateSyncService) }
+
+    context 'with successful template sync' do
+      it 'creates and calls the template sync service' do
+        expect(Twilio::TemplateSyncService).to receive(:new).with(channel: twilio_channel).and_return(template_sync_service)
+        expect(template_sync_service).to receive(:call).and_return(true)
+
+        described_class.perform_now(twilio_channel)
+      end
+    end
+
+    context 'with template sync exception' do
+      let(:error_message) { 'Twilio API error' }
+
+      before do
+        allow(Twilio::TemplateSyncService).to receive(:new).with(channel: twilio_channel).and_return(template_sync_service)
+        allow(template_sync_service).to receive(:call).and_raise(StandardError, error_message)
+      end
+
+      it 'does not suppress the exception' do
+        expect { described_class.perform_now(twilio_channel) }.to raise_error(StandardError, error_message)
+      end
+    end
+
+    context 'with nil channel' do
+      it 'handles nil channel gracefully' do
+        expect { described_class.perform_now(nil) }.to raise_error(NoMethodError)
+      end
+    end
+  end
+
+  describe 'job configuration' do
+    it 'is configured to run on low priority queue' do
+      expect(described_class.queue_name).to eq('low')
+    end
+  end
+end