Refactor state analysis before processing images

The current state shall be correctly analysed before starting any process.

• Filtered images, if required depend on concatenated tiles, and possibly on border masks
• Border Masks, if required depend on concatenated tiles.
• Concatenated tiles depend on orthorectified tiles
• Orthorectified tiles either depend on:
  • input images (fully vertical model)
  • or calibrated & cut images (with cached calibrated & cut images)
• Calibrated & cut images depend on input images
• Input images depend on catalogue of remote files
  • This means, it will interesting to separate (in #7 (closed), #12 (closed)) catalogue fetching from image fetching

Expected directory for each kind of image:

Image type	Directory (as per configuration option name)
Filtered	Output
Border Masks	Output
Concatenated tiles	Output
Orthorectified tiles	tmp
Calibrated & Cut	tmp
Input	S1Images