Rover: add DOCK mode to maneuver vehicle towards docking station automatically

[shiv-tyagi]

This adds a new control mode to rover which would maneuver the vehicle towards docking station automatically. We use the precision landing library to receive the target vectors which we then feed to rover's position controller which gives us the desired speed and lateral acceleration. We also slow down the vehicle based on the ratio of acceptable and measured position error to make the docking more accurate. **This must be merged after #21132 ** Thanks @rmackay9 and @peterbarker for all your valuable guidance throughout.