Simplify IInstallationService interface

[skoshelev]

There is no big point in keeping two methods InstallRequiredData and InstallSampleData in this interface. Instead, we can create one method InstallAsync with the fillSampleData parameter, indicating whether we need to install test data.
This will not only help simplify the interface but also make the code cleaner, for example, it will allow you not to insert the DisplayDefaultMenuItemSettings settings twice.