feat(jwk): Add custom headerName to JWK middleware

[JoaquinGimenez1]

RFC: Enable JWK middleware to read from custom header, similar to the cookie.

This will provider more flexibility for different use cases like Cloudflare Zero Trust Access that sends the assertion token on Cf-Access-Jwt-Assertion header.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.62%. Comparing base (cf0e01e) to head (bdb95f1).
⚠️ Report is 1 commits behind head on next.

Additional details and impacted files

@@           Coverage Diff           @@
##             next    #4279   +/-   ##
=======================================
  Coverage   91.62%   91.62%           
=======================================
  Files         170      170           
  Lines       10836    10837    +1     
  Branches     3225     3159   -66     
=======================================
+ Hits         9928     9929    +1     
  Misses        907      907           
  Partials        1        1           

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[yusukebe]

@JoaquinGimenez1

Thank you for the PR. Can you add proper tests?

[JoaquinGimenez1]

Will add tests and open a proper PR, thanks for the feedback @yusukebe

[JoaquinGimenez1]

Okay, all should be good to go now.

[yusukebe]

LGTM!

[yusukebe]

Hi @JoaquinGimenez1

Thanks! Looks good to me. It's a new feature, so basically it will be introduced in the next minor version, but it's a slight change. So, it may be included in the patch release. I'll decide it later.