Enhancement - Copter - create mission for vertical mapping

Please add the ability to auto-generate mapping missions that allow images to be taken in the vertical plane. As in mapping a cliff or quarry's vertical face.

No files, tests, or entry points are named. Start by locating the existing Copter auto-generated mapping mission flow and tracing how it defines the mapping plane and image-taking waypoints. Done means a mission can be generated for a vertical cliff or quarry face, with images captured across that vertical plane.

Written by the indexing model from the issue text.