remove win32 dependency in favor of ctypes

[hannesdelbeke]

this PR continues on the work from @friedererdmann his PR It removes the dependency on win32gui but without adding a new dependency on keyboards.

• less dependencies is better, since less chance for issues and errors
• this prevents dependency bugs, example mentioned here:

This is because the pywin32 dependency is not installed.

https://github.com/techartorg/bqt/blob/8437e061b74f1a692ef16b2174144cf5e25120f2/setup.py#L91

Currently, you can make it work by manually installing pywin32.