GUI changes for best position angle feature / parallactic angle feature.

The following changes are UI only for OCSADV-23 and subtasks. The logic for best PA for guiding have yet to be completed.
The only problem I see with this is that the way that this information is used requires it to be statically available, and Java doesn't allow static methods to be added to interfaces. This was how I worked around that.

There's probably a way we can change things to be non-static by modifying the PositionAnglePanel class to use init methods instead to initialize the components, which I can look into.