RFR: 8265754: Move suspend/resume API from HandshakeState [v6]

[Anton Artemov]

> Hi,
> 
> in this PR the suspend/resume methods are moved away from the HandshakeState class into a new separate class HandshakeSuspender. The idea is that the state class should be a state keeper and should not be responsible for actions which change the state. Such actions should be done by a separate class. 
> 
> Tested in tiers 1-4.

Anton Artemov has updated the pull request incrementally with two additional commits since the last revision:

 - 8265754: Refactoring into separate file.
 - 8265754: Refactoring.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25407/files
  - new: https://git.openjdk.org/jdk/pull/25407/files/425ec18e..93b87cfa

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25407&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25407&range=04-05

  Stats: 407 lines in 7 files changed: 229 ins; 168 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/25407.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25407/head:pull/25407

PR: https://git.openjdk.org/jdk/pull/25407