Pass privateCollection argument in StubStorage.query()

[Tim-W]

https://github.com/hyperledger-labs/convector/blob/b80312aa90348df3c92ce418b305198ded9a0f10/%40worldsibu/convector-storage-stub/src/stub-storage.ts#L20

This should be changed to:

  public async query(query: any, storageOptions?: any): Promise<any[]> {
    return await this.stubHelper.getQueryResultAsList(query, storageOptions);
  }