[QE] Inline methods in resource classes

I got an advice that we should inline our methods like `waitFor` or `deleteLater` because these methods have really small value and it might be better to get rid of them.

What is inline?
Inlining is used for removing method that is only returns output of another method. So for instance when we have waitFor method that is only returning boolean from ResourceManager.waitForResourceStatus we should remove the waitFor method and keep only the second one.

But the question is if this will not affect semantics and clean of code.