ci: Validate GL_RENDERERs, test a few freedreno driver options

We had some freedreno regressions in UBO support, and we've got some known issues in bypass mode, so add some testing covering those areas. This involved cleaning up a few bits of the deqp-runner script, and while I was there I did a couple of improvements that had been on my mind (validating the reported GL_RENDERER, and disabling compact display everywhere).