Include more logging related to test execution (test start, test end, timestamps)

[rasibley]

For Beaker/Restraint, we can see clearly in the console.log when a test began and ended, this is critical for for kernel debugging (Automotive and RHEL) to identify which test may have caused a kernel panic/oops. Example snippet of how this looks in Restraint when viewing the console.log:

[   85.586564] restraintd[4212]: ** Fetching task: 184687307 [/mnt/tests/distribution/install/tag-repository] 
[   88.398025] restraintd[4212]: ** Preparing metadata 
[   89.399494] restraintd[4212]: ** Refreshing peer role hostnames: Retries 0 
[   90.380893] restraintd[4212]: ** Updating env vars 
[   90.381091] restraintd[4212]: ** Updating external watchdog: 2400 seconds 
[   91.370516] restraintd[4212]: ** Installing dependencies 
[  110.108446] restraintd[4212]: ** Running task: 184687307 [/distribution/install/tag-repository] 
[  112.548781] restraintd[4212]: ** Completed Task : 184687307 

It would be nice if we had a similar capability in tmt/Testing Farm so that more details related to test execution is logged in dmesg which would then be propogated in the console log as well.

[juk]

Similar issue #1409