Initial commit for enabling ground positions. Adds columns to positions
table and ground_position message handler in db-updater, and then add
ground_positions endpoint on fids_backend and also attempt to add ground
position path to maps endpoint.

BCK_6624

Remove comments

Co-authored-by: Chris Roberts <[email protected]>

Remove testing

Co-authored-by: Chris Roberts <[email protected]>

Add comment clarification

Co-authored-by: Chris Roberts <[email protected]>

Previous check for if it was a ground_positions data point just checked
if ground_air was null, now using if its value is "G". Also added
functionality to get top 4 positions and return the top 2 for bearing.

BCK_6624

When trying first 4 coordinates without distingushing them between
ground_positions and positions, bearing was incorrect, so just took the
latest pair between the first two of the two types. Also fixed
coordinate fetching so map has mix but also show plane having both
positions and ground_positions distinguished.

BCK_6624