Don't grab the mouse when debugging

[madebr]

This pr adds 2 main features to make our life easier:

• don't grab the mouse when a debugger is attached.
  This means that, when debugging in an IDE, the mouse won't be hidden.
  Right now, the mouse is hidden when some breakpoint is hit which is annoying.
• do abort() instead of exit(1) on a panic when a debugger is attached,
  such that you are thrown right to the correct spot when e.g. an unimplemented function is encountered.

I copied the code to detect a debugger on Macos from this apple faq page: https://developer.apple.com/library/archive/qa/qa1361/_index.html
There is an important note about the code not working on a release build.
Since I don't own an apple (and you do), can you take a look at this and fix it?
You probably might have to #ifdef _DEBUG this function and return 0 when building a release binary.

This is another way to detect a debugger on Macos
https://zgcoder.net/ramblings/osx-debugger-detection/#mach-exception-handlers

Since gdb is not really used by apply, perhaps this 2nd method should be used instead.

[dethrace-labs]

Seems to work well enough for me - I can build in release mode and it happily runs with no debugger attached. I don't really use a debugger, so I'd be happy enough if the osx one is stubbed with return 0;, but happy to merge as-is for now