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/javascript/shared/helpers/MessageFormatter.js

@@ -1,6 +1,8 @@
+import { escapeHtml } from './HTMLSanitizer';
+
 class MessageFormatter {
   constructor(message) {
-    this.message = message || '';
+    this.message = escapeHtml(message) || '';
   }
 
   formatMessage() {