Chore: Contact Sidebar, conversation cleanup (#908)

- Update sidebar design
- Move every contact data to contacts module
- Revert go to next conversation feature
- Fix issues with new conversation in action cable
- Escape HTML content
- Broadcast event when conversation.contact changes.

Co-authored-by: Sojan <sojan@pepalo.com>

app/models/conversation.rb

@@ -162,7 +162,8 @@ class Conversation < ApplicationRecord
       CONVERSATION_RESOLVED => -> { saved_change_to_status? && resolved? },
       CONVERSATION_READ => -> { saved_change_to_user_last_seen_at? },
       CONVERSATION_LOCK_TOGGLE => -> { saved_change_to_locked? },
-      ASSIGNEE_CHANGED => -> { saved_change_to_assignee_id? }
+      ASSIGNEE_CHANGED => -> { saved_change_to_assignee_id? },
+      CONVERSATION_CONTACT_CHANGED => -> { saved_change_to_contact_id? }
     }.each do |event, condition|
       condition.call && dispatcher_dispatch(event)
     end