Add support for disabling plugins (#4141)

* Move timestamp to own file
* Backend changes
* UI changes

graphql/documents/mutations/plugins.graphql

@@ -9,3 +9,7 @@ mutation RunPluginTask(
 ) {
   runPluginTask(plugin_id: $plugin_id, task_name: $task_name, args: $args)
 }
+
+mutation SetPluginsEnabled($enabledMap: BoolMap!) {
+  setPluginsEnabled(enabledMap: $enabledMap)
+}