workspace list-page: show label

[bertsky]

trafficstars

Sometimes physical page identifiers look like phys_fcd565cd-d170-4774-bb37-9aa25b68370b – which is impossible to type/memorize. But even names like PHYS_0001 are not as helpful as the @ORDERLABEL and @ORDER attributes.

Since presentation systems usually combine the latter two (@ORDER [@ORDERLABEL] IINM) we should offer something of the sort, too.

So ocrd workspace list-page could use an option (for backwards compatibility) to display these labels in extra columns.

But also, the page range operator could be made aware (somehow) of these labels, allowing me to specify, say -g 20 instead of -g phys_fcd565cd-d170-4774-bb37-9aa25b68370b.