Make partition names more descriptive.

### Problem

It can be hard to select the right volumes for partitions as they are listed as /dev/dm{0,1,2,3} and so forth with lvm. I've nearly overwritten some of my other partitions trying when installing Elementary.

### Proposal

Change the display from /dev/dm{0,1,2,3} to /dev/$VOLUMEGROUP/$LV in the installer partition screen where LVM is concerned.

### Prior Art (Optional)

_No response_