feat: support auth_type param

[hperl]

The Facebook OIDC provider supports an auth_type parameter that
when set to "reauthenticate" will force the user to
reauthenticate (similar to `prompt=login` for other Providers).

Related issue(s)

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got the approval (please contact
  [email protected]) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

[codecov]

Codecov Report

Merging #3487 (f753c1e) into master (1e8b1ae) will increase coverage by 0.01%.
Report is 1 commits behind head on master.
The diff coverage is 100.00%.

❗ Current head f753c1e differs from pull request most recent head e60cc98. Consider uploading reports for the commit e60cc98 to get more accurate results

@@            Coverage Diff             @@
##           master    #3487      +/-   ##
==========================================
+ Coverage   78.19%   78.21%   +0.01%     
==========================================
  Files         339      339              
  Lines       22491    22492       +1     
==========================================
+ Hits        17587    17592       +5     
+ Misses       3591     3589       -2     
+ Partials     1313     1311       -2     

Files Changed	Coverage Δ
selfservice/strategy/oidc/provider.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes