feat: use custom auth header name

[amyrprv]

Description

This PR introduces a change that allows the authorization header to be configurable, enabling the use of a custom header name for authorization. Previously, APISIX used a fixed authorization header, but with this update, users can define their own header name in the configuration. This enhancement offers greater flexibility for integrating with systems that require non-standard authorization headers.

Fixes # (issue)

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible

[Baoyuantop]

Hi @amyrprv, there are some conflicts that need to be dealt with.

[amyrprv]

@Baoyuantop Conflicts are resolved, @bzp2010 Tests has been added.

[Baoyuantop]

Hi @amyrprv, there are new conflicts that you need to deal with.

[Baoyuantop]

Hi @amyrprv, any updates?

[amyrprv]

@Baoyuantop Conflicts are resolved

[Baoyuantop]

Hi @amyrprv, some CI failures need to be fixed.

[github-actions]

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[github-actions]

This pull request/issue has been closed due to lack of activity. If you think that is incorrect, or the pull request requires review, you can revive the PR at any time.