Add sled slot number to Inventory > Sleds table/sled view

[hawkw]

oxidecomputer/omicron#11077 adds a slot: Option<u16> to the Sled API response message, containing the physical slot (cubby) number in the rack where that sled was last observed to be located. We should display this in the console when displaying information about a sled. Note that this is the last observed location of the sled and may occasionally be stale if the same sled is removed and reinserted, and may sometimes be null if a sled has just been inserted into the rack.

See also https://rfd.shared.oxide.computer/rfd/0200#_naming_conventions for notes on how location names are formatted in the physical marking of the rack

[benjaminleonard]

Ooh maybe we can visualise their position somehow in a detail view

[hawkw]

@benjaminleonard would love to see what designs you come up with --- this could also be used to add a rack visualization in the main inventory overview somewhere, either in addition to or in place of the inventory table.