Remove all usage of exc_str()

[mih]

Fully implementing http://docs.datalad.org/en/latest/design/exception_handling.html

Fixes #5975

[codecov]

Codecov Report

Merging #6142 (ff81b11) into maint (dccedaf) will increase coverage by 0.37%.
The diff coverage is 69.93%.

❗ Current head ff81b11 differs from pull request most recent head 6550e56. Consider uploading reports for the commit 6550e56 to get more accurate results

@@            Coverage Diff             @@
##            maint    #6142      +/-   ##
==========================================
+ Coverage   85.97%   86.35%   +0.37%     
==========================================
  Files         312      312              
  Lines       42215    42249      +34     
==========================================
+ Hits        36296    36484     +188     
+ Misses       5919     5765     -154     

Impacted Files	Coverage Δ
datalad/distribution/update.py	98.15% <ø> (-0.01%)	⬇️
datalad/downloaders/s3.py	57.36% <0.00%> (-0.59%)	⬇️
datalad/downloaders/tests/test_s3.py	51.63% <0.00%> (+4.88%)	⬆️
datalad/interface/download_url.py	98.11% <ø> (-0.02%)	⬇️
datalad/interface/rerun.py	95.83% <ø> (-0.02%)	⬇️
datalad/interface/results.py	96.92% <ø> (-0.03%)	⬇️
datalad/metadata/extractors/image.py	19.35% <0.00%> (ø)
datalad/metadata/extractors/tests/test_image.py	24.00% <ø> (-2.93%)	⬇️
datalad/support/github_.py	73.07% <0.00%> (-0.18%)	⬇️
datalad/support/sshconnector.py	82.79% <ø> (-0.07%)	⬇️
... and 97 more

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[yarikoptic]

FWIW: I still can't fathom the value of adding a single use ce variable (longer code etc) and not just aliasing exc_str to be CapturedException besides rare cases of debugging whenever the exception manages to bubble up through all the generators and results handling in --dbg mode.

[mih]

FWIW: I still can't fathom the value of adding a single use ce variable (longer code etc) and not just aliasing exc_str to be CapturedException besides rare cases of debugging whenever the exception manages to bubble up through all the generators and results handling in --dbg mode.

I was expecting this comment (again). I will respond in the same fashion as before. I just implemented the concept that was discussed and put in writing. With this PR the concept is fully implemented. We can now start the discussion what the next concept will be, and then we can implement that too. ;-)