Add debugging environment variable that logs when tasks are started in AsyncTaskManager

[OlaviSau]

Is your feature request related to a problem? Please describe.
In our project in order to get happy dom waitUntilComplete working there are some tasks that will never complete.

Describe the solution you'd like
It would be incredibly useful if happy dom had a flag that would enable debug logs on async task manager that logs when a task is started and ended along with the count of tasks. If possible - it would be even better if it provided some info as to the task that was started.

Describe alternatives you've considered
I can also just edit the source code to add the logging myself but I think this will be a common problem for many that are not as capable at debugging.

Additional context
Add any other context or screenshots about the feature request here.

[rossanmol]

I experienced the exact same problem when working happy-dom. It is usually quite simple to use it on a simple application, but then if you had to integrate it with a large application, it starts becoming hard to understand why waitUntilComplete is not completing. Any debug information on this would be so helpful.