The "verbs" in "Testers" API should be more like user actions than Component API replicas

[mstahv]

The "verbs" in "Testers" API should be more like user actions than replicas made of Component API.

e.g. setValue(String) -> fill(String)

Arguments:

1. Test cases would be more like a usage descriptions (especially together with Move away from forcing super class to providing programmatic "user contexts" #38)
2. It wouldn't be that easy to accidentally mix wheter one is using the actual components or simulating user actions on it
3. API would be more like in Playwright, which is more familiar with general audience