Plan: Allow easily bypassing the altitude limit check on mission commands

While planning a mission from the top of a building to a lower landing location I hit this warning.


I knew what I was doing though and I didn't immediately know how to change the Alt limit as suggested. I think it would be nice if the pop-up gave me an option to write it anyway.

The issue names no files, tests, or entry points. Start by reproducing the altitude-limit warning while planning a mission from a high location to a lower landing location; done means the warning offers a way to proceed with the entered command when the user knowingly accepts the altitude difference.

Written by the indexing model from the issue text.