AG FITS for visualization have different contents

At present AG FITS images to sent Gen2 for visualization have three types of images:

1. Taken directly by AGCC actor without centroiding -> only image HDU is saved.
2. Taken directly by AGCC actor with centroiding -> image HDU and tables of detected stars are saved.
3. Taken through AG actor -> image HDU and tables of detected stars and guide candidate stars are saved.

Since there is no flag, it is difficult (simple) to handle the difference. It is better to have empty table in any case, or have a flag of the mode.