decouple eth2 from store and lighthouse_network (#6680)

- #6452 (partially)


  Remove dependencies on `store` and `lighthouse_network`  from `eth2`. This was achieved as follows:

- depend on `enr` and `multiaddr` directly instead of using `lighthouse_network`'s reexports.
- make `lighthouse_network` responsible for converting between API and internal types.
- in two cases, remove complex internal types and use the generic `serde_json::Value` instead - this is not ideal, but should be fine for now, as this affects two internal non-spec endpoints which are meant for debugging, unstable, and subject to change without notice anyway. Inspired by #6679. The alternative is to move all relevant types to `eth2` or `types` instead - what do you think?

beacon_node/http_api/tests/tests.rs

@@ -5686,19 +5686,6 @@ impl ApiTester {
         self
     }
 
-    pub async fn test_get_lighthouse_database_info(self) -> Self {
-        let info = self.client.get_lighthouse_database_info().await.unwrap();
-
-        assert_eq!(info.anchor, self.chain.store.get_anchor_info());
-        assert_eq!(info.split, self.chain.store.get_split_info());
-        assert_eq!(
-            info.schema_version,
-            store::metadata::CURRENT_SCHEMA_VERSION.as_u64()
-        );
-
-        self
-    }
-
     pub async fn test_post_lighthouse_database_reconstruct(self) -> Self {
         let response = self
             .client
@@ -7254,8 +7241,6 @@ async fn lighthouse_endpoints() {
         .await
         .test_get_lighthouse_staking()
         .await
-        .test_get_lighthouse_database_info()
-        .await
         .test_post_lighthouse_database_reconstruct()
         .await
         .test_post_lighthouse_liveness()