Add keyboard shortcut to shift voltage range up/down

[MatthewSteeves]

I'm a big fan of keyboard shortcuts. In using the software, I'm finding that I often get in a situation where I want to shift the voltage trace up on the screen, because maybe a small amount of it is off the screen. There's already keyboard shortcuts to shift left/right along the time axis, so a similar means of shifting up/down would be awesome. (Maybe Shift + Up/Down arrow?)

[EspoTek]

I'll need to make sure those keys aren't mapped, but it seems like a good idea too!