fix(zkstack): Allow to use chain config if ecosystem is redundant (#4236)

## What ❔

Allow to run zkstack command from chain folder, without using the whole
ecosystem.

## Why ❔
Most of the time, for chain operators, it's not necessary to have
ecosystem, it's just enough to have their own chain to make commands on
their chain.

## Is this a breaking change?
- [ ] Yes
- [ ] No

## Operational changes
<!-- Any config changes? Any new flags? Any changes to any scripts? -->
<!-- Please add anything that non-Matter Labs entities running their own
ZK Chain may need to know -->

## Checklist

<!-- Check your PR fulfills the following items. -->
<!-- For draft PRs check the boxes as you complete them. -->

- [ ] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [ ] Tests for the changes have been added / updated.
- [ ] Documentation comments have been added / updated.
- [ ] Code has been formatted via `zkstack dev fmt` and `zkstack dev
lint`.

---------

Signed-off-by: Danil <[email protected]>
Co-authored-by: Alexander Melnikov <[email protected]>

Author: Deniallugo

chains/era/ZkStack.yaml

@@ -2,6 +2,8 @@ id: 1
 name: era
 chain_id: 271
 prover_version: NoProofs
+l1_network: Localhost
+link_to_code: .
 configs: ./chains/era/configs/
 rocks_db_path: ./chains/era/db/
 external_node_config_path: ./chains/era/configs/external_node

core/node/consensus/src/tests/mod.rs

@@ -426,6 +426,7 @@ async fn test_config_change(from_snapshot: bool, version: ProtocolVersionId) {
 // them directly or indirectly.
 #[test_casing(4, Product((FROM_SNAPSHOT,VERSIONS)))]
 #[tokio::test]
+// #[ignore]
 async fn test_full_nodes(from_snapshot: bool, version: ProtocolVersionId) {
     const NODES: usize = 2;