fix(plugins): Add accessor for is_loaded in TemplateColumn

Adds the `accessor` attribute with `tables.A('is_loaded')` to the
`is_installed` column in the plugin's table. This ensures proper data
access and improves the table's functionality.

Fixes #19744

netbox/core/tables/plugins.py

@@ -61,6 +61,7 @@ class CatalogPluginTable(BaseTable):
         verbose_name=_('Local')
     )
     is_installed = columns.TemplateColumn(
+        accessor=tables.A('is_loaded'),
         verbose_name=_('Active'),
         template_code=PLUGIN_IS_INSTALLED
     )