feat: outbound voice call essentials (#12782)

- Enables outbound voice calls in voice channel . We are only caring
about wiring the logic to trigger outgoing calls to the call button
introduced in previous PRs. We will connect it to call component in
subsequent PRs

ref: #11602 

## Screens

<img width="2304" height="1202" alt="image"
src="https://github.com/user-attachments/assets/b91543a8-8d4e-4229-bd80-9727b42c7b0f"
/>

<img width="2304" height="1200" alt="image"
src="https://github.com/user-attachments/assets/1a1dad2a-8cb2-4aa2-9702-c062416556a7"
/>

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Vishnu Narayanan <vishnu@chatwoot.com>

config/routes.rb

@@ -177,6 +177,7 @@ Rails.application.routes.draw do
               resources :contact_inboxes, only: [:create]
               resources :labels, only: [:create, :index]
               resources :notes
+              post :call, on: :member, to: 'calls#create' if ChatwootApp.enterprise?
             end
           end
           resources :csat_survey_responses, only: [:index] do
@@ -550,6 +551,7 @@ Rails.application.routes.draw do
         collection do
           post 'call/:phone', action: :call_twiml
           post 'status/:phone', action: :status
+          post 'conference_status/:phone', action: :conference_status
         end
       end
     end