Zombienet tests - disputes on finalized blocks (#2184)

**Overview:**
Adding an extra malus variant focusing on disputing finalized blocks. It
will:
- wrap around approval-voting
- listen to `OverseerSignal::BlockFinalized` and when encountered start
a dispute for the `dispute_offset`th ancestor
- simply pass through all other messages and signals

Add zombienet tests testing various edgecases:
- disputing freshly finalized blocks
- disputing stale finalized blocks
- disputing eagerly pruned finalized blocks (might be separate PR)

**TODO:**
- [x] Register new malus variant
- [x] Simple pass through wrapper (approval-voting)
- [x] Simple network definition
- [x] Listen to block finalizations
- [x] Fetch ancestor hash
- [x] Fetch session index
- [x] Fetch candidate
- [x] Construct and send dispute message
- [x] zndsl test 1 checking that disputes on fresh finalizations resolve
valid Closes #1365
- [x] zndsl test 2 checking that disputes for too old finalized blocks
are not possible Closes #1364
- [ ] zndsl test 3 checking that disputes for candidates with eagerly
pruned relay parent state are handled correctly #1359 (deferred to a
separate PR)
- [x] Unit tests for new malus variant (testing cli etc)
- [x] Clean/streamline error handling
- [ ] ~~Ensure it tests properly on session boundaries~~

---------

Co-authored-by: Javier Viola <javier@parity.io>
Co-authored-by: Marcin S. <marcin@realemail.net>
Co-authored-by: Tsvetomir Dimitrov <tsvetomir@parity.io>

polkadot/zombienet_tests/functional/0008-dispute-old-finalized.toml

@@ -0,0 +1,40 @@
+[settings]
+timeout = 1000
+
+[relaychain.genesis.runtimeGenesis.patch.configuration.config]
+  max_validators_per_core = 1
+  needed_approvals = 1
+
+[relaychain]
+default_image = "{{ZOMBIENET_INTEGRATION_TEST_IMAGE}}"
+chain = "rococo-local"
+default_command = "polkadot"
+
+[relaychain.default_resources]
+limits = { memory = "4G", cpu = "2" }
+requests = { memory = "2G", cpu = "1" }
+
+  [[relaychain.node_groups]]
+  name = "honest"
+  count = 6
+  args = ["-lparachain=debug"]
+
+  [[relaychain.nodes]]
+  image = "{{MALUS_IMAGE}}"
+  name = "malus"
+  command = "malus dispute-finalized-candidates"
+  args = [ "--alice", "-lparachain=debug,MALUS=trace", "--dispute-offset=14" ]
+
+[[parachains]]
+id = 2000
+
+  [parachains.collator]
+  image = "{{COL_IMAGE}}"
+  name = "collator"
+  command = "undying-collator"
+  args = ["-lparachain=debug"]
+
+[types.Header]
+number = "u64"
+parent_hash = "Hash"
+post_state = "Hash"