[jdk17u-dev] RFR: 8292717: Clean up checking of testing requirements in configure

[Aleksey Shipilev]

Prepares build system for cleaner googletest and jtreg dependency updates. After this, at least googletest update applies only with minor conflicts. I expect jtreg updates would be smoother too.

I did this PR by reverting JDK-8292716 and JDK-8292763 fixes, applying this move cleanly, and then reapplying the first two cleanly. See commit history for individual commits. This makes sure we do not miss anything in backports.

@GoeLin, you might want to take a look.

Additional testing:
 - [ ] GHA

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Commit messages:
 - Clean backport: JDK-8292763: JDK-8292716 breaks configure without jtreg
 - Clean backport: JDK-8292716: Configure should check that jtreg is of the required version
 - Clean backport JDK-8292717: Clean up checking of testing requirements in configure
 - Revert "8292716: Configure should check that jtreg is of the required version"

Changes: https://git.openjdk.org/jdk17u-dev/pull/1693/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1693&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292717
  Stats: 348 lines in 4 files changed: 174 ins; 172 del; 2 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1693.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1693/head:pull/1693

PR: https://git.openjdk.org/jdk17u-dev/pull/1693