feat(bal): scaffold BAL store abstraction

crates/node/builder/src/rpc.rs

@@ -1483,11 +1483,24 @@ where
 /// This provides a basic default implementation for opstack and ethereum engine API via
 /// [`EngineTypes`] and uses the general purpose [`EngineApi`] implementation as the builder's
 /// output.
-#[derive(Debug, Default)]
+#[derive(Debug, Clone)]
 pub struct BasicEngineApiBuilder<PVB> {
     payload_validator_builder: PVB,
 }
 
+impl<PVB> BasicEngineApiBuilder<PVB> {
+    /// Creates a new instance from the payload validator builder.
+    pub fn new(payload_validator_builder: PVB) -> Self {
+        Self { payload_validator_builder }
+    }
+}
+
+impl<PVB: Default> Default for BasicEngineApiBuilder<PVB> {
+    fn default() -> Self {
+        Self::new(PVB::default())
+    }
+}
+
 impl<N, PVB> EngineApiBuilder<N> for BasicEngineApiBuilder<PVB>
 where
     N: FullNodeComponents<