RFR: 8326949: Authorization header is removed when a proxy Authenticator is set on HttpClient [v8]

[Michael McMahon]

> Hi,
> 
> I closed https://github.com/openjdk/jdk/pull/21249 and am continuing the review on this PR.
> 
> This fix relaxes the constraints on user set authentication headers. Currently, any user set authentication headers are filtered out, if the HttpClient has an Authenticator set. The reason being that the authenticator is expected to manage authentication. With this fix, it will be possible to use pre-emptive authentication through user set headers, even if an authenticator is set. The expected use case is where the authenticator would manage either proxy or server authentication and the user set headers would manage server authentication if the authenticator is managing proxy (or vice versa).
> 
> A CSR will be filed to document this change.
> 
> Thanks,
> Michael

Michael McMahon has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 13 additional commits since the last revision:

 - Merge branch 'master' into 8326949-authorize-v2
 - updated apidoc
 - Merge branch '8326949-authorize-v2' of https://github.com/Michael-Mc-Mahon/jdk into 8326949-authorize-v2
 - Update src/java.net.http/share/classes/jdk/internal/net/http/Stream.java
   
   Co-authored-by: Daniel Jelinski <djelinski1 at gmail.com>
 - Update src/java.net.http/share/classes/jdk/internal/net/http/AuthenticationFilter.java
   
   Co-authored-by: Daniel Jelinski <djelinski1 at gmail.com>
 - Update src/java.net.http/share/classes/jdk/internal/net/http/AuthenticationFilter.java
   
   Co-authored-by: Daniel Jelinski <djelinski1 at gmail.com>
 - updated test
 - Merge branch 'master' into 8326949-authorize-v2
 - update
 - Jai review
 - ... and 3 more: https://git.openjdk.org/jdk/compare/abf25efb...a794fcb5

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/21408/files
  - new: https://git.openjdk.org/jdk/pull/21408/files/cdc791a4..a794fcb5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21408&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21408&range=06-07

  Stats: 8733 lines in 155 files changed: 6552 ins; 695 del; 1486 mod
  Patch: https://git.openjdk.org/jdk/pull/21408.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21408/head:pull/21408

PR: https://git.openjdk.org/jdk/pull/21408