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/i18n/locale/en/generalSettings.json

@@ -82,6 +82,7 @@
       "conversation_creation": "New conversation",
       "conversation_assignment": "Conversation Assigned",
       "assigned_conversation_new_message": "New Message",
+      "participating_conversation_new_message": "New Message",
       "conversation_mention": "Mention"
     }
   },