The build steps at the start of CI takes about 2 minutes; now that we
have greatly reduced the overall duration, this is not an insignificant
impact.
Add timestamps to the build process to see measure which steps of the
image build take the most time.
* CI: reduce VM resources requests to improve scheduling
* CI: Reduce default jobs; add labels(ci-full/extended) to run more test
* CI: use jobs dependencies instead of stages
* precommit one-job
* CI: Use Kubevirt VM to run Molecule and Vagrant jobs
