3870 simplify auth logic

Description

Refactor domain / repositories implementation of authentication feature. This MR just clean code, it doesn't improve error handling. May be we should look at it as a "review step" in the refacto 🤔

Technical details

• Add PlayStore authentication as a feature of the PlayStoreRepository
• ViewModel delegate most of the business logic to usecase, usecase use repositories, repositories may use DataSources classe to remain easily testables. and that's it for the layers !

Tests

More test should be engaged before releasing this. But it looks more productive to make them after implementing next issues of this epic of refacto.

Issues

https://gitlab.e.foundation/e/os/backlog/-/issues/3870

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