Anchor pre-PR: Modularize validator store (#6771)

* pass slots_per_epoch at runtime

* remove generic E from unrequired types

* move `validator_store` to `lighthouse_validator_store`

* make validator_store into a trait

* further reduce dependencies

* remove `environment` dependency on `beacon_node_fallback`

* Manually pull in some changes from tracing-integration (thanks sayan!)

Co-authored-by: ThreeHrSleep <threehrsleep@gmail.com>

* remove `environment` from `validator_services`

* unify boost factor accessors

* add builder for DutiesService

* Manually merge tracing PR for beacon_node_fallback

Co-authored-by: ThreeHrSleep <threehrsleep@gmail.com>

* Fix chain_spec for BlockService

* address review

* remove PhantomData from SyncDutiesMap

* fix tests

* correct test

* Add `E` to `ValidatorStore` as associated type

* fix tests

* derive Clone for ValidatorStore's Error and required sub-errors

* switch to enum for block signing to allow differing types

---------

Co-authored-by: João Oliveira <hello@jxs.pt>
Co-authored-by: ThreeHrSleep <threehrsleep@gmail.com>
Co-authored-by: Jimmy Chen <jimmy@sigmaprime.io>

validator_client/lighthouse_validator_store/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "lighthouse_validator_store"
+version = "0.1.0"
+edition = { workspace = true }
+authors = ["Sigma Prime <contact@sigmaprime.io>"]
+
+[dependencies]
+account_utils = { workspace = true }
+doppelganger_service = { workspace = true }
+initialized_validators = { workspace = true }
+parking_lot = { workspace = true }
+serde = { workspace = true }
+signing_method = { workspace = true }
+slashing_protection = { workspace = true }
+slog = { workspace = true }
+slot_clock = { workspace = true }
+task_executor = { workspace = true }
+types = { workspace = true }
+validator_metrics = { workspace = true }
+validator_store = { workspace = true }