Input refactor + AutoHotkey handler for Windows

[Jobus0]

• keyboard_handler has been refactored into a module named input_apis, where each api is a self-contained file. Changed word 'keyboard' to 'input' since AutoHotkey has mouse support, which should be added to pynput_handler as well.
• Implemented AutoHotkey wrapper as a more reliable replacement to the keyboard package on Windows. (Thanks to @j4byers)
• AutoHotkey uses very different hotkey syntax, for example instead of ctrl+shift+r it does +^r. So I wrote a hotkey string conversion function so we can keep using the same old hotkey style. Needs more testing.
• The AutoHotkey package is added to requirements.txt with sys_platform == 'win32' to only install on Windows.

[ILikeAI]

Awesome work again man, thanks so much for the effort here!

[j4byers]

Glad to help. FYI I was doing some research and there is an equivalent (well, similar) python package for Linux (both KDE and Gnome/Ubuntu implementations), called autokey: https://github.com/autokey/autokey.

I haven't used a desktop Linux environment in a while, but I have a raspberry pi lying around somewhere. If I have time this week I'll play around with it and see if it is viable. The major thing is it has a native mouse API, and looking briefly at the documentation, it looks like it would be pretty straight forward to match and translate the hotkeys.