feat: conversation participants (#4145)

Fixes #241
Fixes: chatwoot/product#648

Co-authored-by: Aswin Dev P.S <aswindevps@gmail.com>
Co-authored-by: Nithin David Thomas <1277421+nithindavid@users.noreply.github.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/javascript/dashboard/mixins/specs/uiSettings.spec.js

@@ -120,6 +120,7 @@ describe('uiSettingsMixin', () => {
         { name: 'conversation_info' },
         { name: 'contact_attributes' },
         { name: 'previous_conversation' },
+        { name: 'conversation_participants' },
       ]);
     });
   });