Add sanity-check-manual test case

This commit splits the sanity-check test case into a specific manual
version of it (sanity-check-manual).

This will solve the issue of overwriting automated tests results for
this test case on the qa-report-app.

The name sanity-check is preserved for the automated version so there is
no need to apply any changes to the LAVA jobs.

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>