update python scripts to python3

daemon/binding/python: show warning if not running on Python 3

daemon/binding/python: remove hash bang from btstack_server

daemon/binding/python: improve event pretty print

daemon/binding/python: retry connect for 3 seconds

daemon/binding/python: event factory, makefile

daemon/binding/python: event factory

daemon/binding/python: event factory

daemon/binding/python: lower case function names and params

daemon/binding/python: finish command_builder

daemon/binding/python: custom types

daemon/binding/python: poc