add event on debugger heartbeat and timeout (#49437)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49437

* Log every heartbeat with the same sampling as CDP commands (`debugger_heartbeat`)
* Log abandoned connections due to heartbeat timeout (`debugger_timeout`)

Changelog:
[General][Added] - add inspector proxy events for debugger heartbeat (sampled) and abandoned connections

Reviewed By: robhogan

Differential Revision: D69603217

fbshipit-source-id: f40721f5dc0cc0c33e71a0d29aa50ccf4e7fee3f