[jdk17u-dev] RFR: 8292876: Do not include the deprecated userinfo component of the URI in HTTP/2 headers

[Goetz Lindenmaier]

I would like to fix this issue along with the large http2 remake of 17.
Clean backport, but needed to add edits of  8295944: Move the Http2TestServer and related classes into a package of its own
that was already backported.

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Commit messages:
 - parts from 8295944: Move the Http2TestServer and related classes into a package of its own
 - backport b30d922009bab114fb8ac200df42b594a72a2942

Changes: https://git.openjdk.org/jdk17u-dev/pull/3794/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3794&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292876
  Stats: 124 lines in 2 files changed: 121 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3794.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3794/head:pull/3794

PR: https://git.openjdk.org/jdk17u-dev/pull/3794