Update EpochDuty RPC and core functionality

validator_client/src/duties/traits.rs

@@ -8,12 +8,13 @@ pub enum BeaconNodeError {
 
 /// Defines the methods required to obtain a validators shuffling from a Beacon Node.
 pub trait BeaconNode: Send + Sync {
-    /// Get the shuffling for the given epoch and public key.
+    /// Gets the duties for all validators.
     ///
-    /// Returns Ok(None) if the public key is unknown, or the shuffling for that epoch is unknown.
-    fn request_shuffling(
+    /// Returns a vector of EpochDuties for each validator public key. The entry will be None for
+    /// validators that are not activated.
+    fn request_duties(
         &self,
         epoch: Epoch,
         pubkeys: &[PublicKey],
-    ) -> Result<Option<EpochDuties>, BeaconNodeError>;
+    ) -> Result<Vec<Option<EpochDuties>>, BeaconNodeError>;
 }