Feature request: snap on (charcell) grid

[bestouff]

Hi,
I'd like to have the terminal window and subwindows (when having several terminal panes) be able to snap on grid on resize operations (including font size changes). This is especially needed when you have a big (e.g. fullscreen) Tilix window with several panes and you want to avoid losing lines and columns because of a non-charcell-exact pane size. This would also get rid of dead zones between panes (even if it can't avoid every dead zone, in case of fullscreen windows ou panes with differing font sizes).