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>

app/javascript/dashboard/components-next/icon/specs/provider.spec.js

@@ -19,6 +19,12 @@ describe('useChannelIcon', () => {
     expect(icon).toBe('i-ri-whatsapp-fill');
   });
 
+  it('returns correct icon for Voice channel', () => {
+    const inbox = { channel_type: 'Channel::Voice' };
+    const { value: icon } = useChannelIcon(inbox);
+    expect(icon).toBe('i-ri-phone-fill');
+  });
+
   describe('Email channel', () => {
     it('returns mail icon for generic email channel', () => {
       const inbox = { channel_type: 'Channel::Email' };