RFR: 7903572: JMH: mempool should capture Direct/Mapped memory pools as well

Fri Oct 20 16:30:12 UTC 2023

In this PR I am adding the support for Direct/Mapped Memory pools in the `MemPoolProfiler`.
In my case, it was needed because I suppose a memory leak in the third-party library that unmaps `MappedByteBuffer`.

-------------

Commit messages:
 - 7903572: JMH: Refactor: small fixes. Remove useless line breaker & adjust the code to standards
 - 7903572: JMH: Refactor memory pool results & add them to total
 - Remove non-used parts, rename used results
 - Add support for Direct/Mapped memory pools in the MemPoolProfiler

Changes: https://git.openjdk.org/jmh/pull/124/files
 Webrev: https://webrevs.openjdk.org/?repo=jmh&pr=124&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903572
  Stats: 7 lines in 1 file changed: 7 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jmh/pull/124.diff
  Fetch: git fetch https://git.openjdk.org/jmh.git pull/124/head:pull/124

PR: https://git.openjdk.org/jmh/pull/124