Handle additional DAP events

[nbfalcon]

Here is a list of events: https://microsoft.github.io/debug-adapter-protocol/specification#Events. We currently don't handle all of them; they should be added to the dap--on-event.

The message "No message handler for ..." indicates that we don't implement some event.

[MarkCWirt]

So, it's been three years. I assume that there is no desire to support this feature (allowing remote debugging in debugpy)?

I searched the code base for the dap-on-event referenced above, but couldn't find anything.

It's a shame because dap-mode is great. (Is anyone using it for serious Python development?)

[MarkCWirt]

OK, I think I have found an issue. The code-base was old, and imported ptvsd. Under debugpy things seem to work. As ptvsd is deprecated, this isn't an issue.

Thanks again for this great package!