Split the VC into crates making it more modular (#6453)

* Starting to modularize the VC

* Revert changes to eth2

* More progress

* More progress

* Compiles

* Merge latest unstable and make it compile

* Fix some lints

* Tests compile

* Merge latest unstable

* Remove unnecessary deps

* Merge latest unstable

* Correct release tests

* Merge latest unstable

* Merge remote-tracking branch 'origin/unstable' into modularize-vc

* Merge branch 'unstable' into modularize-vc

* Revert unnecessary cargo lock changes

* Update validator_client/beacon_node_fallback/Cargo.toml

* Update validator_client/http_metrics/Cargo.toml

* Update validator_client/http_metrics/src/lib.rs

* Update validator_client/initialized_validators/Cargo.toml

* Update validator_client/signing_method/Cargo.toml

* Update validator_client/validator_metrics/Cargo.toml

* Update validator_client/validator_services/Cargo.toml

* Update validator_client/validator_store/Cargo.toml

* Update validator_client/validator_store/src/lib.rs

* Merge remote-tracking branch 'origin/unstable' into modularize-vc

* Fix format string

* Rename doppelganger trait

* Don't drop the tempdir

* Cargo fmt

validator_client/src/check_synced.rs

@@ -1,27 +0,0 @@
-use crate::beacon_node_fallback::CandidateError;
-use eth2::{types::Slot, BeaconNodeHttpClient};
-use slog::{warn, Logger};
-
-pub async fn check_node_health(
-    beacon_node: &BeaconNodeHttpClient,
-    log: &Logger,
-) -> Result<(Slot, bool, bool), CandidateError> {
-    let resp = match beacon_node.get_node_syncing().await {
-        Ok(resp) => resp,
-        Err(e) => {
-            warn!(
-                log,
-                "Unable connect to beacon node";
-                "error" => %e
-            );
-
-            return Err(CandidateError::Offline);
-        }
-    };
-
-    Ok((
-        resp.data.head_slot,
-        resp.data.is_optimistic,
-        resp.data.el_offline,
-    ))
-}