[NEVER MERGE] ZN test for asserting building Parablocks on RC with session change

[Sajjon]

[!CAUTION] Do not merge, the assert here should be negated and then added as a commit to #9990

@skunert I'm asking you to review this as a proper way of asserting that we ARE building parablocks where RC or Parent of RC contains session change.

If this code indeed is correct (but probably can be cleaned up), I will then invert the asserts, and commit it on top of #9990