More tests for OperationQueue/Operaion

There are some issues in current implementation. To keep things simple, I'd like to extend
test coverage of problem area first. Not all of new tests are expected to fail, but I find them useful
to have.

Co-authored-by: Andrew Druk <[email protected]>
Co-authored-by: Anton Pogonets <[email protected]>

Author: 3 people