[browser][coreCLR] exit/abort/logging infra for unit testing

[pavelsavara]

• load dotnet.diagnostics.js early when available in the boot config
• add internal support for unit testing via dotnet.diagnostics.js
  • skeleton of symbolicateStackTrace
  • exitOnUnhandledError
  • appendElementOnExit
  • logExitCode
  • asyncFlushOnExit
  • forwardConsole
• new internal MSbuild property <WasmTestSupport>true</WasmTestSupport> which deploys dotnet.diagnostics.js
• new internal MSbuild properties WasmTestExitOnUnhandledError, WasmTestAppendElementOnExit, WasmTestLogExitCode, WasmTestAsyncFlushOnExit, WasmTestForwardConsole
• set WasmTestSupport for library tests and WBT
• implemented abortStartup(), abortTimers(), abortPosix()
• implemented isExited(), isRuntimeRunning()
• invoke LoadBootResourceCallback for Blazor
• invoke Module.onConfigLoaded and Module.onDotnetReady
• captures ExitStatus type
• capture posix/emscripten abort()/exit() events
• fixed locateFile - for query string propagation
• hides BrowserHost_InitializeCoreCLR, BrowserHost_ExecuteAssembly from Module exports
• reporting not found assemblies to debug log
• make dotnet.run() to not call exit() and keep runtime alive.
  • This will be breaking change for CoreCLR vs Mono.
  • Because previous behavior was just confusing everyone.

Fixes #101169
Fixes #75335
On top of #122616
On top of #122495