General: New Integrator small fixes

[iLLiCiTiT]

Brief description

Fixed few smaller issues in integrator and cleaned up code and comments.

Description

Minimum frame padding is defined by last frame of sequence instead of first frame (999 vs. 1000). Frame padding fom anatomy template is always considered when frame should be filled. Replaced AssertionErrors with KnownPublishError. Added "output" to representation context keys and removed explicit set of it at the end. Make sure that representation context has filled first frame during sequence processing. Removed comments marking logic as backwards compatibility which is still fully required and does not have any replacement.

Testing notes:

• Integration should work
• Integrated representation filenames should at all costs have filled frame with padding from anatomy templates or lenght of last frame (in case anatomy templates padding is 4 but last frame is e.g. "10000" - in that case padding should be 5)
  • even if frames of input filepaths have padding of 6