BF: get_versioned_url - support anonymous acces (no provider) and buckets with . in name

[yarikoptic]

No description provided.

[codecov]

Codecov Report

Merging #4985 into maint will increase coverage by 0.04%.
The diff coverage is 92.85%.

@@            Coverage Diff             @@
##            maint    #4985      +/-   ##
==========================================
+ Coverage   89.86%   89.91%   +0.04%     
==========================================
  Files         292      292              
  Lines       40730    40740      +10     
==========================================
+ Hits        36604    36630      +26     
+ Misses       4126     4110      -16     

Impacted Files	Coverage Δ
datalad/support/s3.py	39.62% <87.50%> (+15.10%)	⬆️
datalad/tests/test_s3.py	56.00% <100.00%> (+6.00%)	⬆️
datalad/downloaders/http.py	81.85% <0.00%> (-3.09%)	⬇️
datalad/downloaders/tests/test_http.py	88.22% <0.00%> (-2.89%)	⬇️
datalad/distribution/create_sibling.py	85.02% <0.00%> (-0.57%)	⬇️
datalad/downloaders/base.py	80.70% <0.00%> (-0.36%)	⬇️
datalad/downloaders/s3.py	41.53% <0.00%> (+1.02%)	⬆️

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[yarikoptic]

and thank you @kyleam for the review