#563 Improve CIF data-synthesis main fixed point loop sections

• Changes: clearer comments to indicate which section belongs to which operation.
• Dedicated 'end of fixed point loop' detections for 2nd and 3rd operations. No more split or shared functionality.
• All changes of this branch are backward compatible. None of these changes change synthesis behavior (hence to test output has changed either). Only the code is changed to make it easier to follow.
• I made separate commits to reduce the Git diff per commit as much as possible. The one where indentation is changed looks complicated, but only two code blocks changed indentation.
• I know a lot else can be improved in the data-based synthesis tool, but the only goal here is to make the sections dedicated per operation, and to then make it clear to which operation each section belongs.

Closes #563 (closed)