make failsafe_trigger switch pixhawk to RTL mode via `VehicleCommand`

[ethayu]

should be possible
this is what chat says:

so you should emulate what this function runs

monorepo/controls/sae_2025_ws/src/uav/uav/UAV.py

Line 141 in 7fc05a7

def hover(self):

except with the correct params from

monorepo/controls/sae_2025_ws/src/uav/uav/px4_modes.py

Line 12 in 7fc05a7

class PX4CustomMainMode(FloatEnum):