RFR: 7902788: RunTestsCommand should print Total/Setup/Cleanup times in a more human readable way

[Dmitry Bessonov]

Curently RunTestsCommand class prints the total exec time upon run completion the following way, always giving only the number of seconds:

Total time = 0s
Total time = 323s
Total time = 2,949s
This is to improve total time logging, shaping it in a more human-readable way, for example

`Total time: 5 minutes 32 seconds `

Same formatting looks reasonable to apply to setup and cleanup time.

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Commit messages:
 - 7902788: RunTestsCommand should print Total/Setup/Cleanup times in a more human readable way - minor change cleanup
 - 7902788: RunTestsCommand should print Total/Setup/Cleanup times in a more human readable way

Changes: https://git.openjdk.java.net/jtharness/pull/7/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jtharness&pr=7&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7902788
  Stats: 228 lines in 3 files changed: 221 ins; 1 del; 6 mod
  Patch: https://git.openjdk.java.net/jtharness/pull/7.diff
  Fetch: git fetch https://git.openjdk.java.net/jtharness pull/7/head:pull/7

PR: https://git.openjdk.java.net/jtharness/pull/7