RFR: 8350964: Add an ArtifactResolver.fetch(clazz) method

[Matthew Donovan]

In this PR, I created a new method, `ArtifactResolver.fetchOne()`, to consolidate duplicate code across tests.

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Commit messages:
 - 8350964: Add an ArtifactResolver.fetch(clazz) method

Changes: https://git.openjdk.org/jdk/pull/23989/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23989&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350964
  Stats: 93 lines in 5 files changed: 41 ins; 37 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/23989.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23989/head:pull/23989

PR: https://git.openjdk.org/jdk/pull/23989