SCORU/Tezt: add the following test scenario

The following discussion from !5646 (merged) should be addressed:

• @iguerNL started a discussion:

  Add a tezt test on top of this one with the scenario:

     [test_cement_order_and_forks] starts by publishing a bench of
     commitments following the scenario below:
     ---- pub C1 ---- pub C2 ---- pub C3 ---- pub C41
                                           \- pub C42
  
     Then, it bakes sufficiently many blocks to be able to (theoretically) cement
     all commitments. After that:
     - It tries to cement C2: this should fail
     - It tries to cement C1 and then C2: this should succeed
     - It tries to cement C3: this should fail
     - It tries to cement C41 or C42: either should fail