Add handler to fetch all of the system permissions and load them into the state

resources/scripts/api/getSystemPermissions.ts

@@ -0,0 +1,10 @@
+import { SubuserPermission } from '@/state/server/subusers';
+import http from '@/api/http';
+
+export default (): Promise<SubuserPermission[]> => {
+    return new Promise((resolve, reject) => {
+        http.get(`/api/client/permissions`)
+            .then(({ data }) => resolve(data.attributes.permissions))
+            .catch(reject);
+    });
+};