cogl/tests: Use less verbose run-tests.sh on single tests run by meson

Use less verbose output when run-tests.sh is running only a test and we're
requested for less verbose output.

Also write the test name first of running it.

GNOME/mutter!442
3 jobs for !442 with meson-test-suites in 8 minutes and 56 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Review
passed #275216
check-commit-log

00:01:16

 
  Build
passed #275217
build-mutter

00:01:56

 
  Test
passed #275218
test-mutter

00:05:43