Support scrolling the terminal

[joshka]

Is your feature request related to a problem? Please describe.
Let's say we have a command that outputs a bunch of data to the terminal, some of which causes the terminal to scroll. I'd like some way to cause the terminal to scroll up to see the previous data in the gif.

My specific use case for this is in Ratatui (a rust TUI lib) testing that we can insert information before the current viewport (writable part of the screen for an app), and that this is in the correct position after the draw.

Describe the solution you'd like
Two commands ScrollUp N and ScrollDown N that scroll by a number of rows

Describe alternatives you've considered
I'm not sure if there is a generic way to do this with keyboard shortcuts (most apps will not pass PageUp/PageDown to the terminal in a way that's useful)

Additional context
Looking for less manual ways to test ratatui-org/ratatui#596

[maaslalani]

Yes, we should certainly have this as well as other mouse controls. One thing I would change about the API is to introduce negative numbers as a way to scroll up lines (possibly):

Scroll 5 # scroll down 5 lines
Scroll -5 # scroll up 5 lines

[joshka]

Makes sense