message: Improve unknown value type error message
diff: @@ -605,7 +605,7 @@ export class SharedMap extends SharedObject implements ISharedMap {
  const valueType = this.getValueType(remote.type);
  translatedValue = valueType.factory.load(new MapValueOpEmitter(remote.type, key, this), remote.value);
  } else {
  - return Promise.reject("Unknown value type");
  + return Promise.reject(`Unknown value type "${remote.type}"`);
  }
  return {
  