Please add more detailed logging to Param

### My Pain

I'm a user of Panel and thus of Param. I'm using the reactive API in Panel i.e. developing using `@param.depends`.

Sometimes things are not working as expected and I need to identify the root cause. Often I end up adding `print` statements to understand which events are triggered and in which order.

This takes time to add and clean up.

### Solution

Add functionality to monitor which events are emitted and which watchers they are emitted to.

Maybe the functionality is simple logging functionality that can be turned on by setting the logging level to debug.

### Additional Context

When using front end frameworks like react or angular I can use https://chrome.google.com/webstore/detail/redux-devtools/lmhkpmbekcpmknklioeibfkpmmfibljd?hl=en which provides me with information on which events and state changes that occur. That is a more general/ abstract solution than I need. But maybe it can help inspire what is needed.

FYI @philippjfr . You asked me to add this.