Fix planned home position set when takeoff has no coordinate in it

Fix terrain NaN making it all the way to Planned Home altitude.

Fix resume mission item count bug

Fix Change Command parameter default setting

Don't add takeoff as first item when it doesn't make sense for vehicle

Otherwise things like gimbal angles end up on the wrong items.

Number calc doesn't work so hiding for now

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>