Graph elevation profile for mission and display violations of constraints

See [here](https://youtu.be/z5lNbsgY3FA?si=dEhsONsX0r7SbnGm&t=843) for an example in UgCS:


Graph the mission plan, with elevation on the Y axis. One line shows the estimated path of the drone (requires knowing climb/descent angle of the UAV and how it will get between each waypoint). The bottom graph shows the terrain.

Next, add bands for the minimum and maximum allowable AGL, and any MSL restrictions from fences.

Finally, highlight any conflicting areas and show what is wrong along the route. Consider highlighting mission segments in violation of constraints in red.

Consider how to extend the validators to custom restrictions such a LOS plugins or similar.

Start by mapping the existing mission validators and the terrain, waypoint, and fence data they use; the issue does not name files or tests. Define the elevation-profile entry point, constraint bands, violation highlighting, and an extension path for custom restrictions, then verify the display against the linked example and representative constrained routes.

Written by the indexing model from the issue text.