RFR: 8351187: Add JFR monitor notification event [v3]

[Aleksey Shipilev]

> We have `JavaMonitorWait` event, but no symmetric `JavaMonitorNotify` event. Notifications are important/interesting to track as well, for example to correlate the delay between notification and eventual wake up.
> 
> Providing this event would also replace one of of the RT counters that are going away in [JDK-8348829](https://bugs.openjdk.org/browse/JDK-8348829).
> 
> This counter is disabled by default to keep any potential impact low. We can consider flipping it to enabled by default later.
> 
> Additional testing:
>  - [x] Linux x86_64 server fastdebug, `jdk_jfr`

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Rewrite test to RecordingStream

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23901/files
  - new: https://git.openjdk.org/jdk/pull/23901/files/bae0c391..f52144fd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23901&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23901&range=01-02

  Stats: 72 lines in 1 file changed: 34 ins; 27 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/23901.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23901/head:pull/23901

PR: https://git.openjdk.org/jdk/pull/23901