Fix cursor position after alt screen resize

This fixes a regression introduced in 4cc6421, which ignored the main
grid's cursor when increasing the number of lines available, causing
incorrect cursor position after restoring to the primary screen.

Additionally another similar bug has been fixed where the grid was not
scrolled correctly when shrinking while in the alternate screen.

When the grid is resized multiple lines at once, there was also an issue
with Alacritty either pulling all lines from history or none at all,
instead of mixing both approaches and pulling just what is required.
This lead to incorrect cursor positions when the resize could partially
make use of history.

Fixes #3499.

0 files changed, 0 insertions, 0 deletions