RFR: 7903543: Making Agent's connections more NIO friendly [v2]

[Dmitry Bessonov]

> This is for refactoring few JT agent's helper classes to support and work with SocketChannels

Dmitry Bessonov has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Merge branch 'openjdk:master' into CODETOOLS-7903543
 - minor cleanups
 - minor cleanups
 - 7903543: Making Agent's connections more NIO friendly

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Changes:
  - all: https://git.openjdk.org/jtharness/pull/51/files
  - new: https://git.openjdk.org/jtharness/pull/51/files/22e87205..63367012

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jtharness&pr=51&range=01
 - incr: https://webrevs.openjdk.org/?repo=jtharness&pr=51&range=00-01

  Stats: 11 lines in 2 files changed: 1 ins; 5 del; 5 mod
  Patch: https://git.openjdk.org/jtharness/pull/51.diff
  Fetch: git fetch https://git.openjdk.org/jtharness.git pull/51/head:pull/51

PR: https://git.openjdk.org/jtharness/pull/51