TargetDiskHints should support glob matching

[tjjh89017]

internal/diskmatch.Match compares every hint field exactly. A machine whose disk name or serial is not known in advance cannot be described.

Decided shape:

• Every field accepts a glob, not just the device name. Serial numbers often carry a fixed vendor prefix, so a glob is useful there too.
• When a glob matches more than one disk, sort the matches in string order and take the smallest — sd* against sda and sdb selects sda.
• The tiebreak exists because a glob is the only way to reach more than one match. An exact hint that matched several disks would still be an error, as it is today: the controller requires exactly one match before any write.

Not scheduled.