Major rework to support terrain profile display and terrain collision reporting

Out Survey polygons with KML save

Survey And Corridor now share same transect generation code. Better unit tests for both with more coverage.

Major rewrite of Survey generation for simplicity. Also includes support for CONDITION_GATE.

Mavlink terrain protocol support

New Create Plan support

Handle cross fact update internally

Pattern Preset support

Rework complex distance, camera shot count calc for better back compat

Fix swapped climb/descent

Only adjust existing waypoints. Does not add waypoints.