feat: Line Channel (#2904)

- Ability to configure line bots as a channel in chatwoot
- Receive a message sent to the line bot in chatwoot
- Ability to reply to line users from chatwoot

fixes: #2738

app/models/inbox.rb

@@ -93,6 +93,15 @@ class Inbox < ApplicationRecord
     }
   end
 
+  def webhook_url
+    case channel_type
+    when 'Channel::TwilioSMS'
+      "#{ENV['FRONTEND_URL']}/twilio/callback"
+    when 'Channel::Line'
+      "#{ENV['FRONTEND_URL']}/webhooks/line/#{channel.line_channel_id}"
+    end
+  end
+
   private
 
   def delete_round_robin_agents