RFR: 8274: Add thread counts to the Java Application page

[Marcus Hirt]

Added all of them, but perhaps only having active and daemon would be good enough.

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Commit messages:
 - 8274: Adding thread counts to the Java Application page

Changes: https://git.openjdk.org/jmc/pull/600/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=600&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8274
  Stats: 56 lines in 6 files changed: 54 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jmc/pull/600.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/600/head:pull/600

PR: https://git.openjdk.org/jmc/pull/600