RF: Copy get_key_url from datalad.support.s3

[effigies]

datalad/datalad#7575 is failing because the crawler wants to import a function that uses boto objects.

[codecov]

Codecov Report

Attention: Patch coverage is 63.63636% with 4 lines in your changes missing coverage. Please review.

Project coverage is 77.53%. Comparing base (2929e3b) to head (a636bd3).

Files	Patch %	Lines
datalad_crawler/nodes/s3.py	63.63%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #143      +/-   ##
==========================================
- Coverage   77.56%   77.53%   -0.04%     
==========================================
  Files          60       60              
  Lines        4721     4731      +10     
  Branches      956      959       +3     
==========================================
+ Hits         3662     3668       +6     
- Misses        895      898       +3     
- Partials      164      165       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[yarikoptic]

THANK YOU @effigies