Exception Handling for Frame connection information (CK coverage)

It is well known that when no CK information is available for a reference frame, SPICE throws an exception. This is perfectly fine. Nevertheless a tool like this should be able to provide to the user different options on how to handle these exceptions given that, especially for measured CKs, CK files have gaps and if present this will make these operational CK files un-usable.

My proposal is to notify GAPS in CK data and whenever possible, in plots, show the existing data and leave the CK gaps as gaps in the plot.

In addition the user should also be able to activate or deactivate this behavior in order to be able to catch CK coverage gaps as exceptions if needed.