[BUGFIX] Use correct implementation of fetching current frontend user

* Fix outdated implementation to fetch current frontend user
* Use better labels for buttons

Closes: #536, #537
9 jobs for 537-notify-me-via-email-on-new-releases in 6 minutes and 19 seconds (queued for 7 seconds)
Name Stage Failure
test:rector Test
         files in "$parameters->set(Option::AUTOLOAD_PATHS, [...]);" or         
"$parameters->set(Option::BOOTSTRAP_FILES, [...]);" in "rector.php"
See https://github.com/rectorphp/rector#configuration".

! [NOTE] 2 files were added

Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1