feat: make PayloadBuilderHandle pub (#5578)

crates/payload/builder/src/service.rs

@@ -78,7 +78,11 @@ pub struct PayloadBuilderHandle {
 // === impl PayloadBuilderHandle ===
 
 impl PayloadBuilderHandle {
-    pub(crate) fn new(to_service: mpsc::UnboundedSender<PayloadServiceCommand>) -> Self {
+    /// Creates a new payload builder handle for the given channel.
+    ///
+    /// Note: this is only used internally by the [PayloadBuilderService] to manage the payload
+    /// building flow See [PayloadBuilderService::poll] for implementation details.
+    pub fn new(to_service: mpsc::UnboundedSender<PayloadServiceCommand>) -> Self {
         Self { to_service }
     }
 
@@ -349,7 +353,7 @@ type PayloadFuture =
     Pin<Box<dyn Future<Output = Result<Arc<BuiltPayload>, PayloadBuilderError>> + Send + Sync>>;
 
 /// Message type for the [PayloadBuilderService].
-pub(crate) enum PayloadServiceCommand {
+pub enum PayloadServiceCommand {
     /// Start building a new payload.
     BuildNewPayload(
         PayloadBuilderAttributes,