mouse input events don't seem to indicate if the event is a drag or not

[tstack]

It doesn't look like the ncinput structure has a way to indicate if a mouse input event is a drag or not (i.e. the user moves the mouse while holding down a button). The mouse tracking escape sequences add 32 to the button number to indicate a drag, but this seems to be lost in this code:

https://github.com/dankamongmen/notcurses/blob/3a3c75e65ac8342f10a0e16eb63ab642aaf52ef4/src/lib/in.c#L614-L625

Please include the following data:

• notcurses version (available from notcurses-demo i)

v3.0.11