BFT synchronizer: integration test against an orderer that does block censorship

- Run a 4 orderer smart bft cluster.
- Do 5 TXs.
- Shut down o4.
- Do 5 more TXs.
- Shutdown o1,o2,o3
- Prepare 3 orderer mocks with 10 TXs, with the addresses of o1,o2,o3
   - same mocks as used in the peer test
   -  emulate block censorship
- Start o4
- O4 should detect the block censorship attempt and get all 10 blocks to its ledger