Offloading KZG Proof Computation from the beacon node (#7117)

Addresses #7108

- Add EL integration for `getPayloadV5` and `getBlobsV2`
- Offload proof computation and use proofs from EL RPC APIs

beacon_node/execution_layer/src/test_utils/mod.rs

@@ -58,6 +58,7 @@ pub const DEFAULT_ENGINE_CAPABILITIES: EngineCapabilities = EngineCapabilities {
     get_payload_v5: true,
     get_client_version_v1: true,
     get_blobs_v1: true,
+    get_blobs_v2: true,
 };
 
 pub static DEFAULT_CLIENT_VERSION: LazyLock<JsonClientVersionV1> =