[jdk11u-dev] RFR: 8253820: Save test images and dumps with timestamps from client sanity suite

[Andrew Lu]

I backport this for parity with 11.0.23-oracle.

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Commit messages:
 - Backport e32a4ea4efc284eb004201a6cb77eb0404460bfd
 - Backport ffc97ba585b3750a0fe0d29d39a1201d91954d0f

Changes: https://git.openjdk.org/jdk11u-dev/pull/2404/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2404&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8253820
  Stats: 200 lines in 4 files changed: 105 ins; 37 del; 58 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2404.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2404/head:pull/2404

PR: https://git.openjdk.org/jdk11u-dev/pull/2404