Add command to goto certain position

[Matthijsy]

This PR adds a new command to goto a certain grid position, without cycling through the different dimensions. For example if you want to have a screen on the left 1/3 you have to run the left command twice. However with this new command you can run goto-1/3-1. If you want to have the 2/3 you currently have to run the left command 3 times, now you can do goto-2/3-1. If you want it in the upper 2/3 in the right corner you can run goto-2/3-2-top.

The code does automatically adapt to the amount of columns that are defined. Some of the commands might be duplicate (like goto-2/4-1 and goto-1/2-1 are the same), but that is not an issue I suspect.

Would really love to receive some feedback on this idea

[ssokolow]

Sorry for taking so long to respond. I'm a bit busy jugging a few things right now, so I haven't had time to look at the PR, but I'll leave this tab open as a reminder.