ContextDeserialize and Beacon API Improvements (#7372)

* #7286
* BeaconAPI is not returning a versioned response when it should for some V1 endpoints
* these [strange functions with vX in the name that still accept `endpoint_version` arguments](https://github.com/sigp/lighthouse/blob/stable/beacon_node/http_api/src/produce_block.rs#L192)

This refactor is a prerequisite to get the fulu EF tests running.

Cargo.lock

@@ -1665,6 +1665,26 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
+[[package]]
+name = "context_deserialize"
+version = "0.1.0"
+dependencies = [
+ "milhouse",
+ "serde",
+ "ssz_types",
+]
+
+[[package]]
+name = "context_deserialize_derive"
+version = "0.1.0"
+dependencies = [
+ "context_deserialize",
+ "quote",
+ "serde",
+ "serde_json",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "convert_case"
 version = "0.4.0"
@@ -9390,6 +9410,8 @@ dependencies = [
  "bls",
  "compare_fields",
  "compare_fields_derive",
+ "context_deserialize",
+ "context_deserialize_derive",
  "criterion",
  "derivative",
  "eth2_interop_keypairs",