Print queue group printer selection#175

Allow printer & printer model (#174) selection in print queue groups, making all queued items in the given group only match with / be printable on printers / printer models / printer groups, that the group has selected.

Furthermore, the printer selection can be narrowed down on each individual print queue item; say the group has 2 printer models selected; on one item, you can then define a specific printer (or multiple), within the parent selection parameters, to be the selection for the specific queue item.

Will make it easier to have a print queue group for different printer types & brands, such as a Prusa queue and a Bambu Lab queue, as they use different files, but the Bambu Lab printers can in theory accept files from the Prusa queue in most instances.