Implemented comment thread target picker with new dropdown components (#295)

* First draft of new relation picker and usage in comments
---------

Co-authored-by: Charles Bochet <charles@twenty.com>

front/src/modules/comments/services/select.ts

@@ -25,6 +25,10 @@ export const GET_COMMENT_THREADS_BY_TARGETS = gql`
           avatarUrl
         }
       }
+      commentThreadTargets {
+        commentableId
+        commentableType
+      }
     }
   }
 `;
@@ -44,6 +48,10 @@ export const GET_COMMENT_THREAD = gql`
           avatarUrl
         }
       }
+      commentThreadTargets {
+        commentableId
+        commentableType
+      }
     }
   }
 `;