Currently, `DriveScannerService` is in charge of both scanning the
available drives and maintaining the state of the currently detected
drives.
To honour the single responsibility principle, we split this service
into a `DrivesModel`, which is incharge of maintaining the state without
caring how they are detected, and `DriveScannerService`, which only
scans the available drives and modified `DrivesModel` accordingly.
Signed-off-by: Juan Cruz Viotti <jviottidc@gmail.com>
This refactoring will be useful on future changes, where there will be
a single application entry point that will execute the CLI or the GUI
version depending on the environment.
Signed-off-by: Juan Cruz Viotti <jviottidc@gmail.com>
