Enhancement: Point Camera Here feature extended to Flight Planner

The feature "point camera here" is a great one while directing the unit on the fly which would add significant functionality if it was extended to the flight planner. Precise missions could be setup for flight paths and also directing what to have the camera look at and when. Camera gimbal control could be utilized including tilt which the angle would be a function of altitude and vertical distance to the point of interest.

Start by locating the existing "point camera here" feature and the flight planner implementation in Mission Planner. Review how flight paths and camera gimbal tilt are currently represented, then define the required mission behavior and verify that precise camera directions can be configured for planned flight paths.

Written by the indexing model from the issue text.