RFR: 8378276: Refactor test/jdk/java/net/httpclient/quic/ TestNG tests to JUnit

[Daniel Fuchs]

TestNG tests located under test/jdk/java/net/httpclient/quic/ are refactored to use JUnit.
 Mostly mechanical - a couple of `assertEquals` calls had to be turned into `assertArrayEquals`.

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

Commit messages:
 - 8378276: Refactor test/jdk/java/net/httpclient/quic/ TestNG tests to JUnit

Changes: https://git.openjdk.org/jdk/pull/29841/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29841&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378276
  Stats: 798 lines in 17 files changed: 77 ins; 123 del; 598 mod
  Patch: https://git.openjdk.org/jdk/pull/29841.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29841/head:pull/29841

PR: https://git.openjdk.org/jdk/pull/29841