RFR: 8349910: Implement JEP 517: HTTP/3 for the HTTP Client API [v9]

[Daniel Fuchs]

> Hi,
> 
> Please find here a PR for the implementation of [JEP 517: HTTP/3 for the HTTP Client API](https://openjdk.org/jeps/517).
> 
> The CSR can be viewed at [JDK-8350588: Implement JEP 517: HTTP/3 for the HTTP Client API](https://bugs.openjdk.org/browse/JDK-8350588)
> 
> This JEP proposes to enhance the HttpClient implementation to support HTTP/3.
> It adds a non-exposed / non-exported internal implementation of the QUIC protocol based on DatagramChannel and the SunJSSE SSLContext provider.

Daniel Fuchs has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 525 commits:

 - merge latest changes from master branch
 - http3: run H3StreamLimitReachedTest.java with -Djdk.httpclient.http3.maxStreamLimitTimeout=0 too
 - retry the ResetControlStream test as needed
 - http3: fix pending connection and reconnection on stream limit reached logic
 - http3: pending acknowledgement should be registered before actually sending the packet
 - http3: fix race with ping requests in PacketSpaceManager.java causing intermittent failures in H3ErrorHandlingTest.java
 - http3: improve exceptions in Http3ServerExchange.java
 - http3: fix exception handling in CancelRequestTest.java
 - http3: review feedback - revert HPACK.java
 - Implement X509TrustManagerImpl#checkClientTrusted for QUIC
 - ... and 515 more: https://git.openjdk.org/jdk/compare/5a1301df...0229c215

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Changes: https://git.openjdk.org/jdk/pull/24751/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24751&range=08
  Stats: 105143 lines in 471 files changed: 102311 ins; 1336 del; 1496 mod
  Patch: https://git.openjdk.org/jdk/pull/24751.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24751/head:pull/24751

PR: https://git.openjdk.org/jdk/pull/24751