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?

common/warp_utils/Cargo.toml

@@ -9,7 +9,6 @@ edition = { workspace = true }
 bytes = { workspace = true }
 eth2 = { workspace = true }
 headers = "0.3.2"
-metrics = { workspace = true }
 safe_arith = { workspace = true }
 serde = { workspace = true }
 serde_array_query = "0.1.0"