Support to execution test by steps.#177

We have manual checklists consisting of a series of steps, and we want to be able to take the test step by step, marking each step as passed or failed.

As you understand some steps from the checklist may be broken, but broken steps do not equal broken functionality.

Currently, I was able to implement this on your system, but it turned out that each step is displayed as a separate test. This is a problem since the automated test for this will be one and will contain all the steps described.