stty: add options to set and print terminal size

[willshuttleworth]

fixes for #3859. adds options for setting the size of the terminal's rows and columns, and printing the current size.

• stty rows <n>
• stty columns <n> or stty cols <n>
• stty size

i did add some new unsafe blocks, as ioctl calls are needed to get and set terminal size. i couldn't find documentation of what row/col sizes are accepted by GNU's stty, but i did some testing and am matching their behavior. i also added tests to confirm this behavior.

[github-actions[bot]]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)

[github-actions[bot]]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

[cakebaker]

Thanks :)

[willshuttleworth]

thanks for reviewing!