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/shared/components/ui/MultiselectDropdownItems.stories.js

@@ -10,7 +10,7 @@ export default {
         type: 'object',
       },
     },
-    selectedItem: {
+    selectedItems: {
       control: {
         type: 'object',
       },
@@ -63,5 +63,5 @@ MultiselectDropdownItems.args = {
     },
   ],
 
-  selectedItem: { id: '1' },
+  selectedItems: [{ id: '1' }],
 };