RFR: 8292876: Do not include the deprecated userinfo component of the URI in HTTP/2 headers [v6]

[Darragh Clarke]

> Changed the way the `:authority` pseudo header is set to only include host and, if available, port.
> I added a test to cover this change that consists of a HttpClient that makes a request which contains userInfo, the test passes if the request is carried out with the userInfo not being added to the `:authority` header.
> 
> 
> ### Tests
> I ran Tier 1 - Tier 3 tests, as well as paying special attention to the http client tests to make sure they consistently passed

Darragh Clarke has updated the pull request incrementally with three additional commits since the last revision:

 - check authority pseudoheader directly
 - removed unused import
 - test cleanup

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10592/files
  - new: https://git.openjdk.org/jdk/pull/10592/files/67a3f84b..d2d48054

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10592&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10592&range=04-05

  Stats: 45 lines in 1 file changed: 22 ins; 18 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/10592.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10592/head:pull/10592

PR: https://git.openjdk.org/jdk/pull/10592