Support auto-mounting and ejecting SATA drives

Plinth currently uses udiskie to auto-mount removable storage media. udiskie doesn't seem to support auto-mounting SATA drives.

1. Replace udiskie with a custom implementation (also gets rid of nearly 100MB of dependencies)
2. Detect a SATA drive as removable and show eject button in the UI of the Storage app.

The UX should be the same as auto-mounting and ejecting a USB drive.