RFR: 7903589: JOL: Rework and amend CLI tools

[Aleksey Shipilev]

CLI tools need a few touchups. Heapdump utilities, notably, need more work.

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Commit messages:
 - Work

Changes: https://git.openjdk.org/jol/pull/55/files
 Webrev: https://webrevs.openjdk.org/?repo=jol&pr=55&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903589
  Stats: 1892 lines in 12 files changed: 1721 ins; 73 del; 98 mod
  Patch: https://git.openjdk.org/jol/pull/55.diff
  Fetch: git fetch https://git.openjdk.org/jol.git pull/55/head:pull/55

PR: https://git.openjdk.org/jol/pull/55