TextInput on_submit lacks callback, when all other on_* methods do

[andyblarblar]

Hey all, just figured i'd point out that TextInput on_submit doesn't take a callback, which for me is pretty limiting as an input and seems to break style with the rest of the on_* style methods.

Not sure if there's already been disccussion on this in the past here since I'm new, but this seems like pretty low hanging fruit