add rchk and/or torture CI jobs

[jangorecki]

followup of #3615 (comment)

• long time (24hrs) of torture run might be an issue
• rchk setup with singularity and not docker might be issue too

in both cases most likely solution would be to use private CI runner using ssh, same as we do for windows jobs now.
Another thing is that if those tests returns false positives often? if so it might be difficult to make them useful.

[mattdowle]

torture doesn't have false positives. Although rchk does. it will still be very useful to have rchk results to hand without me having to run it. It doesn't need to be a pass/fail in CI.

[jangorecki]

https://docs.gitlab.com/ee/user/gitlab_com/#linux-shared-runners
Public GLCI runners have 3h timeout, so we will need to plug private runner to handle more time consuming jobs.