make publisher collections transferable to wikidata

[maxlath]

Currently, collections might look something like this:

{
  labels: {},
  claims: {
    'wdt:P31': [ 'wd:Q20655472' ],
    'wdt:P1476': [ 'Nautilus Flugschrift' ],
    'wdt:P123': [ 'wd:Q1285306' ]
  }
}

The title (wdt:P1476) is a simple string, without the language code expected by wikibase-edit for monolingualtext properties such as wdt:P1476:

    'wdt:P1476': [ { text: 'Nautilus Flugschrift', language: 'de' } ],

In other places, the language code is inferred from the language claim (wdt:P407). The same could be done for collections being transferred to wikidata:

• enable wdt:P407 for entities of type collection
• when transferring to wikidata:
  • validate that the collection has a wdt:P407 claim set
  • deduce the language code from the wdt:P407 claim, to propertly reshape the monolingualtext value