Ensure eth1 deposit/chain IDs are used from YamlConfig (#1829)

## Issue Addressed

 NA

## Proposed Changes

Fixes a bug which causes the node to reject valid eth1 nodes.

- Fix core bug: failure to apply `YamlConfig` values to `ChainSpec`.
- Add a test to prevent regression in this specific case.
- Fix an invalid log message

## Additional Info

NA

beacon_node/eth1/src/service.rs

@@ -370,7 +370,7 @@ impl Service {
                     crit!(
                         self.log,
                         "Invalid eth1 network. Please switch to correct network";
-                        "expected" => format!("{:?}",DEFAULT_NETWORK_ID),
+                        "expected" => format!("{:?}",config_network),
                         "received" => format!("{:?}",network_id),
                         "warning" => WARNING_MSG,
                     );