TEX12 — Group metadata angle units can conflict with GeodeticPosition units

Section 7.3.18 the description for GeodeticPosition specifies that "The Angle unit as well as the projection are set by the Group.". However for a WGS84 position this would idiomatically be expected to be in degrees but elsewhere in a TEX entity a system implementer would possibly want to use SI angle units (radians) for other angles on an entity.

We could introduce an additional GeodeticAngleUnit attribute to the metadata to allow geodetics to use different units to other angles in an entity.