Hey everyone,
This mr is related to the issue #987 and add the Field version of StateCovariance. Now that I have made it, I realize that it was most probably not useful for the goal I had in mind but it is too late so I now hope that someone can find a use for it
It also contains fixes for some tests in StateCovarianceTest that need to be implemented anyway, as they are currently false.
Finally, I spotted a small Javadoc error in FieldSpacecraftState and fixed it.
UPDATE
Turns out I actually need it for the collision package so I'm closing this MR and merge it with my future collision package branch.