fix: openid foward original id token

[cgmEdi]

Description

Issue: https://github.com/apache/apisix/issues/10275 https://github.com/apache/apisix/issues/12438 Summary: add a config option "set original id token header" so that the original id_token that was stored in the sesssion (enc_id_token) gets fowarded as the new header "X-Id-Token-Original".

In my company, we have a use case, where the donwstream needs the original id_token so that it can perform a token exchange.

Which issue(s) this PR fixes:

Fixes #10275 #12438

Checklist

• [x] I have explained the need for this PR and the problem it solves
• [x] I have explained the changes or the new features added to this PR
• [x] I have added tests corresponding to this change
• [x] I have updated the documentation to reflect this change
• [x] I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)

[Baoyuantop]

I need to check the original issue before reviewing this PR.

[Baoyuantop]

Hi @cgmEdi, there is a conflicting file that needs to be resolved.

[cgmEdi]

Hi @cgmEdi, there is a conflicting file that needs to be resolved.

Hi @Baoyuantop, the conflict is resolved now :).

[Baoyuantop]

Hi @cgmEdi, please fix failed ci.

[Baoyuantop]

Hi @cgmEdi, any updates?

[Baoyuantop]

The issue associated with this PR has been closed due to lack of activity and no agreement has been reached with the primary maintainer.

[Baoyuantop]

Since there have been no further responses to the comments in the issue https://github.com/apache/apisix/issues/12438#issuecomment-3134684961, we believe the validity of this request is controversial and have decided to close this PR for now. Please feel free to reopen it if you have any further questions. Thank you for your contribution @cgmEdi .