[WIP] Refactor event redrawing

This is an attempt to remove the K_EVENT hack by handling redrawing directly while polling for input. It should also fix some problems:

- Without K_EVENT, we no longer interfere with pending operators(@equalsraf may experienced this at #914)
- Don't need to handle K_EVENT everywhere characters are read, removing the possibility of getting stuck in infinite loops receiving K_EVENT keys(@carlosdcastillo may have experienced this at #781)