RFR: 8310996: Add JFR event for connect operations [v5]

[Tim Prinzing]

> Adds a JFR event for socket connect operations.
> 
> Existing tests TestSocketEvents and TestSocketChannelEvents modified to also check for connect events.

Tim Prinzing has updated the pull request incrementally with one additional commit since the last revision:

  Added more tests for socket connect events.
  
  - SocketAdapter connect
  - SocketAdapter connect with exception
  - Socket connect with exception
  - SocketChannel connect with exception
  - SocketChannel non-blocking connect
  - SocketChannel non-blocking connect with exception

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21528/files
  - new: https://git.openjdk.org/jdk/pull/21528/files/ce9d39e2..13f81570

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21528&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21528&range=03-04

  Stats: 177 lines in 5 files changed: 162 ins; 0 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/21528.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21528/head:pull/21528

PR: https://git.openjdk.org/jdk/pull/21528