feat: Voice channel creation Flow (#11775)

This PR introduces a new channel type for voice conversations.

ref: #11481 

## Changes

- Add database migration for channel_voice table with phone_number and
provider_config
- Create Channel::Voice model with E.164 phone number validation and
Twilio config validation
- Add voice channel association to Account model
- Extend inbox helpers and types to support voice channels
- Add voice channel setup UI with Twilio configuration form
- Include voice channel in channel factory and list components
- Add API routes and store actions for voice channel creation
- Add comprehensive translations for voice channel management

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>

spec/enterprise/controllers/enterprise/api/v1/accounts/inboxes_controller_spec.rb

@@ -22,6 +22,22 @@ RSpec.describe 'Enterprise Inboxes API', type: :request do
         expect(response).to have_http_status(:success)
         expect(JSON.parse(response.body)['auto_assignment_config']['max_assignment_limit']).to eq 10
       end
+
+      it 'creates a voice inbox when administrator' do
+        post "/api/v1/accounts/#{account.id}/inboxes",
+             headers: admin.create_new_auth_token,
+             params: { name: 'Voice Inbox',
+                       channel: { type: 'voice', phone_number: '+15551234567',
+                                  provider_config: { account_sid: "AC#{SecureRandom.hex(16)}",
+                                                     auth_token: SecureRandom.hex(16),
+                                                     api_key_sid: SecureRandom.hex(8),
+                                                     api_key_secret: SecureRandom.hex(16) } } },
+             as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(response.body).to include('Voice Inbox')
+        expect(response.body).to include('+15551234567')
+      end
     end
   end