Tests: replace andWait(XXXXX.millis) with actual check that operation is done

[ptitFicus]

Several tests create entities in Otoroshi and wait a given number of ms before continuing, however in some case provided duration is not enough.

Creation method could "poll" ototoshi for created entity before returning (using stuff like awaitability) to ensure that entity is correctly taken into account before continuing test.
This could avoid some randomly failing tests and even speed up execution in some cases.

[ptitFicus]

Otoroshi exchange protocol V2 got some example of such tests