feat: support multiple origins in webauthn config

[hperl]

Related issue(s)

ory/docs#1474

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
  security@ory.sh) 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

[Benehiko]

Looks good, how will this affect current Webauthn credentials?

[hperl]

That took longer than expected, because the webauthn library silently broke contract by switching the encoding from base64 to base64urlencoded.

[codecov]

Codecov Report

Merging #3380 (7d4b36b) into master (e3fcf0c) will increase coverage by 0.01%.
Report is 3 commits behind head on master.
The diff coverage is 100.00%.

❗ Current head 7d4b36b differs from pull request most recent head d8defe5. Consider uploading reports for the commit d8defe5 to get more accurate results

@@            Coverage Diff             @@
##           master    #3380      +/-   ##
==========================================
+ Coverage   78.02%   78.03%   +0.01%     
==========================================
  Files         327      327              
  Lines       21364    21368       +4     
==========================================
+ Hits        16669    16675       +6     
+ Misses       3457     3456       -1     
+ Partials     1238     1237       -1     

Files Changed	Coverage Δ
identity/credentials_webauthn.go	100.00% <ø> (ø)
selfservice/strategy/webauthn/login.go	62.50% <ø> (ø)
selfservice/strategy/webauthn/registration.go	64.94% <ø> (ø)
driver/config/config.go	82.60% <100.00%> (+0.09%)	⬆️
selfservice/strategy/webauthn/settings.go	65.26% <100.00%> (ø)
selfservice/strategy/webauthn/user.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

[Benehiko]

LGTM

[hperl]

Docs PR: ory/docs#1474