Tests: Allow for version to contain + as a separator and provide more information for version related comparisons

[yarikoptic]

To partially address and provide more information to figure out details of #5785

[yarikoptic]

if no surprises, will merge to make datalad/git-annex fails more informative

[codecov]

Codecov Report

Merging #5786 (ab86083) into maint (f779163) will decrease coverage by 60.79%.
The diff coverage is 0.00%.

❗ Current head ab86083 differs from pull request most recent head 75b1e4b. Consider uploading reports for the commit 75b1e4b to get more accurate results

@@             Coverage Diff             @@
##            maint    #5786       +/-   ##
===========================================
- Coverage   90.33%   29.54%   -60.80%     
===========================================
  Files         300      297        -3     
  Lines       42345    42311       -34     
===========================================
- Hits        38253    12501    -25752     
- Misses       4092    29810    +25718     

Impacted Files	Coverage Δ
datalad/cmdline/tests/test_main.py	0.00% <0.00%> (-98.53%)	⬇️
datalad/support/tests/test_external_versions.py	0.00% <0.00%> (-95.55%)	⬇️
datalad/tests/test_api.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/support/digests.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/tests/test_base.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/tests/test_config.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/ui/tests/__init__.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/tests/test__main__.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/tests/test_strings.py	0.00% <0.00%> (-100.00%)	⬇️
datalad/ui/tests/test_base.py	0.00% <0.00%> (-100.00%)	⬇️
... and 248 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f779163...75b1e4b. Read the comment docs.