Provide regression tests for submitting contesting proofs

[sdaveas]

Operation from , Algorithm 1, line 10 is missing from

---------+---x1---->  Ca
         |
         +--->        Cb

and

---------+-------->   Ca
         |
         +--x2->      Cb

• Create chains Ca and Cb which have a common ancestor block
• Only Ca contains block x1 and only Cb contains x2
• Execute the following:
  1.|Ca| > |Cb|: Execute submit_event_proof(Ca, x1) and submit_contesting_proof(Cb, x1)
  2.|Ca| > |Cb|: Execute submit_event_proof(Cb, x2) and submit_contesting_proof(Ca, x2)

---

Update

Pn denotes the proof that was generated for chain Cn

x0 contained in Pa and Pb

---x0---+-------->  Ca
        |
        +--->       Cb

test case	expected output	reason	received output
submit_event_proof(Pa, x0)	TRUE	x0 in Ca	TRUE
submit_contest_proof(Pb, x0)	FALSE	|Cb| < |Ca|; existing proof is stronger	FALSE
--
submit_event_proof(Pb, x0)	TRUE	x0 in Cb	TRUE
submit_contest_proof(Pa, x0)	FALSE		FALSE

x1 contained in Pa but not in Pb

--------+---x1--->  Ca
        |
        +--->       Cb

test case	expected output	reason	received output
submit_event_proof(Pa, x1)	TRUE	x1 in Ca	TRUE
submit_contest_proof(Pb, x1)	FALSE	|Cb| < |Ca|; existing proof is stronger	FALSE
--
submit_event_proof(Pb, x1)	FALSE	x1 not in Cb	FALSE
submit_contest_proof(Pa, x1)	FALSE	event x1 is not mapped yet	FALSE

x2 contained in Pb but not in Pb

--------+---------->  Ca
        |
        +--x2-->      Cb

test case	expected output	reason	received output
submit_event_proof(Ca, x2)	FALSE	x2 not in Ca	FALSE
submit_contest_proof(Cb, x2)	FALSE	event x2 is not mapped yet	FALSE
--
submit_event_proof(Cb, x2)	TRUE	x2 in Cb	TRUE
submit_contest_proof(Ca, x2)	TRUE	|Ca| > |Cb| and x2 not in Ca; honest chain does not include 'x2'	TRUE

[sdaveas]

It seems that the assignment of proof π is not missing. It is done inside the verify() function.