[lldb/test] Fix TestProgressReporting.py race issue with the event listener

This patch is a follow-up of D120100 to address some feedbacks from
@labath.

This should mainly fix the race issue with the even listener by moving
the listener setup to the main thread.

This also changes the SBDebugger::GetProgressFromEvent SWIG binding
arguments to be output only, so the user don't have to provide them.

Finally, this updates the test to check it the out arguments are returned
in a tuple and re-enables the test on all platforms.

Differential Revision: https://reviews.llvm.org/D120284



Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>