libfdisk: add partition type aliases and shortcuts

libfdisk: add partition type aliases and shortcuts

Now, the type shortcuts are supported for sfdisk scripts only.

Unfortunately, the current implementation is not generic enough
and it's also fragile as 'E' shortcut is in collision with 0x0E
type for MBR. The another issue is 'L' which makes shortcuts useless
for fdisk where 'L' is used for another purpose in dialogs.

This patch introduces partition type aliases as extension to
shortcuts. The definition of the shortcut is part of the label
definition and it's not more hardcoded in sfdisk script code.

This patch also introduces 'Ex' shortcut as replacement for (now
deprecated) 'E'.

Signed-off-by: Karel Zak <kzak@redhat.com>