Python2 removal multiple scripts

[jennfshr]

@bschwal this removes python2 from OVIS-4

bash-4.4$ grep -r "/usr/bin/env python2" rpmbuild/BUILD/    
rpmbuild/BUILD/ovis-ldms-4.4.3/ldms/src/sampler/shm/mpi_profiler/wrap/wrap.py:#!/usr/bin/env python2  
rpmbuild/BUILD/ovis-ldms-4.4.3/ldms/src/sampler/filesingle/ldms-sensors-config:#! /usr/bin/env python2  
rpmbuild/BUILD/ovis-ldms-4.4.3/ldms/scripts/ldms-csv-export-sos:#! /usr/bin/env python2  
rpmbuild/BUILD/ovis-ldms-4.4.3/ldms/scripts/ovis-roll-over.py:#!/usr/bin/env python2  
rpmbuild/BUILD/ovis-ldms-4.4.3/ldms/scripts/ldms-csv-anonymize:#! /usr/bin/env python2

I still need to do some testing to ensure I didn't introduce any bad syntax. Evan and I plan on testing this early this week. If you have a chance, please review.

[tom95858]

@jennfshr did you and Evan get a chance to test this?

[baallan]

I'm working my way through review and test.
I see in addition to 2->3 porting, there's quite a bit of variable name cleanup and commented debugging statements removal. Most of these changes are improving readability, so i'm fine with it being all in one PR.

[baallan]

Created jennfshr#2 of suggested changes to this pr.