Rename ViewModel to LifecycleViewModel

[dasdranagon]

Why

Currently, the name of ViewModel is a bit confusing and doesn't explicitly describe what it does. In fact, it makes an impression that the class is meant to be used as a parent for all view models. However, it is meant to be used to manage the lifecycle and you don't have to (and shouldn't) use it on all your screen.

Because we are already using ViewModel in most of our projects it makes sense to create an alias and mark it as deprecated before actually deleting it.

[thoutbeckers]

Discussed in kaluga meeting to do this