message: improving assertion message to include more info
diff: @@ -474,7 +474,9 @@ export class FluidDataStoreRuntime extends EventEmitter implements IFluidDataSto
  assert(this.pendingAttach.has(id), "Unexpected attach (local) channel OP");
  this.pendingAttach.delete(id);
  } else {
  - assert(!this.contexts.has(id), "Unexpected attach channel OP");
  + assert(!this.contexts.has(id), `Unexpected attach channel OP,
  + is in pendingAttach set: ${this.pendingAttach.has(id)},
  + is local channel contexts: ${this.contexts.get(id) instanceof LocalChannelContext}`);
  // Create storage service that wraps the attach data
  const origin = message.origin?.id ?? this.documentId;
  