Raft scenarios falsifying Heidi's hypothesis about raft.h's behavior.

Execute with:

```shell
.../build $ python3 ../tests/raft_scenarios_runner.py ./raft_driver ../tests/raft_scenarios/5879_deprecated
    ```

tests/raft_scenarios/5879_deprecated

@@ -0,0 +1,65 @@
+nodes,0,1
+connect,0,1
+
+# Node 0 starts first, and begins sending messages first
+periodic_one,0,110
+dispatch_all
+
+periodic_all,30
+dispatch_all
+
+state_all
+assert_is_primary,0
+assert_is_backup,1
+
+## ... with the same logs upto index 7.
+replicate,1,txAtIdx1
+replicate,1,txAtIdx2
+replicate,1,txAtIdx3
+replicate,1,txAtIdx4
+replicate,1,txAtIdx5
+replicate,1,txAtIdx6
+emit_signature,1
+periodic_all,30
+dispatch_all
+
+assert_commit_idx,0,7
+assert_commit_idx,1,0
+
+periodic_all,30
+dispatch_all
+assert_state_sync
+
+assert_commit_idx,0,7
+assert_commit_idx,1,7
+
+## At index 8, the leader n2 reconfigures to remove n1.
+replicate_new_configuration,1,0
+
+periodic_all,30
+dispatch_all
+
+state_all
+assert_is_primary,0
+assert_is_backup,1
+## Index 9 is a signature, index 10 some random transaction and index 11 is a signature. 
+emit_signature,1
+assert_commit_idx,0,7
+
+replicate,1,txAt10
+assert_commit_idx,0,7
+
+emit_signature,1
+assert_commit_idx,0,7
+
+
+## When the ACI action taken by n2, it should be able to commit index 11 but instead it will commit index 9.
+periodic_all,30
+dispatch_all
+
+assert_is_primary,0
+assert_is_backup,1
+assert_is_retired,1
+
+assert_commit_idx,0,11
+assert_commit_idx,1,7