[Devices Management] Refactor some code to improve testability

[mnaturel]

Your use case

What would you like to do?

We should create a new clean copy of the existing “DevicesViewModel” into the V2 package. We should encapsultate all domain layer inside testable small UseCases.

Why would you like to do it?

To improve test coverage. And to ease readability of the code.

How would you like to achieve it?

• ViewModel is clean and tested
• All introduced use cases are tested
• ViewState and other model classes are in their own class

Have you considered any alternatives?

No response

Additional context

No response

Are you willing to provide a PR?

Yes