Additional and adjusted logging for parallel minor GC. (mono/mono#17522)

Additional and adjusted logging for parallel minor GC. (mono/mono#17522)

* Additional and adjusted logging for parallel minor GC.

When running parallel minor GC we currently get incorrect timing
on several loggings and counters due to work being put on thread pool
and accumulated. This commit fix so that the logging is accurate
when running with and without parallelization. In parallel mode a new
logging is also added to show the accumulated split between major and los
remset scan jobs.

The counters time_minor_scan_remsets and time_minor_scan_roots are only
updated when not running parallel GC since they are not correct when
running parallel GC.

* Fix WASM build error.

Commit migrated from https://github.com/mono/mono/commit/c5edcd1ed443ae5b960d8f8972b0850b7999e44a