UDisks backend: improve the description of volume and storage devices

- Nowadays SSD's are pretty common, using "Hard Drive" doesn't seem correct,
  "Hard Disk Drive" v.s. "Solid State Drive". Instead use: "External Drive"
  and "Internal Drive", which should work for both cases

- Add the block device name (sdX[Y]) to the description, this is useful for
  devices without labels; the same goes for a whole disk device, e.g.
  /dev/sdc, which can't have a label at all.
  One can easily differentiate between devices based on the device name,
  /dev/sda, /dev/sdc2, /dev/sdd ...etc, which are always unique

An obvious use-case is the Places panel in Dolphin or KFileWidget, if you
have two or more partitions without labels, you can't tell which is which
easily with just the size.

BUG: 410891
FIXED-IN: 5.84