fix(data-editor): enable apply button after row deletion

handleDeleteRow() was missing the notifyPendingChanges() call, so the
apply/reset buttons stayed disabled after deleting rows from the table.

Author: Mnikley

src/utilities/data_editor.js

@@ -497,6 +497,8 @@ class DataTable {
       if (this.onChangeCallback) {
         this.onChangeCallback(-1, -1, 'row_deleted');
       }
+
+      this.notifyPendingChanges();
     }
   }