feat: Telegram Channel (#2901)

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

fixes: #1843

app/models/channel/web_widget.rb

@@ -26,8 +26,10 @@
 
 class Channel::WebWidget < ApplicationRecord
   include FlagShihTzu
-
   self.table_name = 'channel_web_widgets'
+  EDITABLE_ATTRS = [:website_url, :widget_color, :welcome_title, :welcome_tagline, :reply_time, :pre_chat_form_enabled,
+                    { pre_chat_form_options: [:pre_chat_message, :require_email] },
+                    { selected_feature_flags: [] }].freeze
 
   validates :website_url, presence: true
   validates :widget_color, presence: true