Problem: missing redraws when restoring saved cursorline/column, plus missing
statusline and mode redraws when not updating the screen in terminal mode.
Solution: schedule the redraws in a similar manner to other modes and remove
some now unnecessary redrawing logic. Redraw if cursorline-related options
change from entering terminal mode. This fixes test failures in later commits.
WTF: TextChangedT triggers based on must_redraw, which is... fun...? Try to
preserve its behaviour as much as we can for now.