Feature request: fakegps set yaw, pitch, speed, Fix state, virtually run a mission

Hi,
At 1st thanks so much for the long waited fakegps feature.
I've been using an old tool called Ramzibi GPS EMULATOR_ConfigTool
It could only be found on [archive](https://web.archive.org/web/20100106180942/http://www.happykillmore.com/Software/RemzibiOSD/Waypoints/ConfigTool.zip)
It provided many useful features.

Inspired by the old tool, I hope you can enhance this modules by allow movement:
1. Allow to set a yaw/ground course direction
2. Set the ground speed
3. Allow moving up or down by altering the pitch/vertical course

Also, it would be nice if you can allow to alter GPS fix state, allowing to test 2D fix and states higher than 3D fix.

One last feature that shouldn't block the previous features is to run a mission virtually. So after arming I run `fakegps runwaypoints groundspeed waypoints.file`

Start by reading and running the existing fakegps module and command behavior. Define how yaw, ground speed, pitch or vertical movement, GPS fix states, and virtual mission execution should work, including the proposed `fakegps runwaypoints groundspeed waypoints.file` form. Done means these requested simulation controls can be exercised after arming and produce the intended movement and fix states.

Written by the indexing model from the issue text.