Allow zpool status -c to also specify vdev properities

[tonyhutter]

Describe the feature would like to see added to OpenZFS

It would be nice to include specific vdev properties in the zpool status output. We could overload zpool status -c to specify them:

$ zpool get fragmentation,ashift tank U0
NAME                  PROPERTY       VALUE  SOURCE
U0                    fragmentation  4%     -
U0                    ashift         12     -

$ zpool status -c fragmentation,ashift
  pool: tannk
 state: ONLINE
  scan: scrub repaired 0B in 00:00:58 with 0 errors on Mon Dec  2 14:58:51 2024
config:

	NAME                   STATE     READ WRITE CKSUM fragmentation ashift
	tank                   ONLINE       0     0     0            
	  mirror-0             ONLINE       0     0     0            4%     12
	    U0                 ONLINE       0     0     0            5%     12
	    U2                 ONLINE       0     0     0            2%     12
	    U4                 ONLINE       0     0     0            1%     12

The only name conflict between the -c scripts columns and the vdev params is "size", which we can probably work around. We'd want a test case to make sure there were no naming conflicts between the scripts columns and vdev properties too.

How will this feature improve OpenZFS?

Make it easier to see per-vdev values in the familiar zpool status column output.

Additional context

This makes it easier to tack on new state to vdevs. For example, we wouldn't have needed special zpool status cases for slow IOs (-s) if we had this functionality earlier. It also makes it so you don't have do separate zpool status -j and zpool get -j calls if you're trying to query pool status and vdev properties for JSON.