tickit_term_erasech() erases count character cells forward from the current cursor location, using the
current pen background colour.
Some terminals cannot erase using the background colour, so this operation may be implemented by printing
spaces on such terminals. This will move the cursor to the end of the erased region. Other terminals that
do erase with background colour can be erased without moving the cursor. The moveend parameter controls
the behaviour of the cursor location when this function returns. If set to TICKIT_YES, the cursor will be
moved to the end of the erased region if required. If set to TICKIT_NO, the cursor will be moved back to
its original location if required. If set to TICKIT_MAYBE, this function will take whichever behaviour is
more optimal on the given terminal.