suite: use owner value for user name

[zmc]

pulpito-ng is gaining the ability to kill runs, and for non-admin users will match the user's github username with the test run's owner value to decide if the user is allowed to kill the run (admin users can kill any run). To generate the run name, we normally use the active user account's name.

It could be confusing if a user passed --owner but then still sees their unix account name used to name the run; this change lets us use more consistent naming without adding yet another flag (--user) to teuthology-suite.

Edit: The pulpito-ng PR: ceph/pulpito-ng#51

[VallariAg]

If I understand it right, the run's username and owner both will be set to value of --owner input with this PR?

In the current implementation of pulpito-ng's kill-run, we check if run belongs to user by looking at the owner (which is stored at job level) and never decide ownership based on the username. So if you use --owner zmc then pulpito-ng should see you as the owner of the run even if the run name starts with "zack-". Let me know if that's not the case!

Here are ownership checks in:
t-api: https://github.com/ceph/teuthology-api/pull/55/files#diff-02d3c9819201f270bdf30499d8e189622dc5d969e96d6582aef93f0e9e029c48R31-R33

pulpito-ng:

1. https://github.com/ceph/pulpito-ng/pull/51/files#diff-aeb4ab3acaee02c9aa9c960ec5ee9b3e56c316802dc7e7ae0284b5702016c027R59
2. https://github.com/ceph/pulpito-ng/pull/51/files#diff-5db46c41bfe3b6e18f278e8721577a9c75851c2f3e6e519a61b6fe54a74d7b03R39

[zmc]

Thanks @VallariAg for pointing out my conflation of terms - the change is more about making the run name consistent with what the user might expect. I've reworded the PR description and cleaned up the code a little more to make things more clear.