Add the "http_token" authentication mechanism which provides 'Authentication: Token {TOKEN}' header

[yarikoptic]

It is pretty much the "Bearer TOKEN" method but which uses different keyword "Token". It is e.g. the one provided by Django REST Framework. GitHub allows for both 'Bearer' and 'Token' keywords: https://docs.github.com/en/rest/authentication/authenticating-to-the-rest-api?apiVersion=2022-11-28

In our case of DANDI we ran into it only now that we decided to add handling of embargoed datasets, for which we need to authenticate to access the files. We are using Django REST Framework and insofar decision was made to retain current approach (and fix WWW-Authentication header response), instead of an alternative to allow for both 'Bearer' and 'Token' as was suggested in dandi/dandi-archive#1830

As it is ad-hoc (nothing AFAIK in W3C standard) Authentication response I do not think some automation would ever be created based on WWW-Authentication but we will be able to support such providers.

PR checklist

• Provide an overview of the changes you're making and explain why you're proposing them.
• Create a changelog snippet (add the CHANGELOG-missing label to this pull request in order to have a snippet generated from its title;
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[yarikoptic]

fails unrelated (test_gh2043p1 on OSX and then ftp ones on windows appveyor) -- restarting

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (08315c1) 91.16% compared to head (532a5c6) 91.23%.

Additional details and impacted files

@@            Coverage Diff             @@
##            maint    #7551      +/-   ##
==========================================
+ Coverage   91.16%   91.23%   +0.07%     
==========================================
  Files         325      325              
  Lines       43440    43446       +6     
  Branches     5785     5785              
==========================================
+ Hits        39600    39640      +40     
+ Misses       3825     3791      -34     
  Partials       15       15              

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[yarikoptic]

ok, there were no objections and now we fixed all the rest and have datasets on github which need this. So I will merge and would be happy to address concerns later.

[yarikoptic-gitmate]

PR released in 0.19.6