implemented processing of /user/openid_login?service=X

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/Components/Login.svelte

@@ -10,6 +10,8 @@
     const router    = useTinyRouter();
     let services    = $state([]);
 
+
+
     function doLogin(ev){
         ev.preventDefault();
         tryLogin(credentials);
@@ -46,6 +48,8 @@
         ev.preventDefault();
         router.navigate('/user/reset/pw');
     }
+
+    if (router.fullPath.endsWith('/openid_login') && router.query.service) redirectTo(router.query.service);
 </script>
 
 <style>