refs #219

This makes it possible to add arbitrary choices that may not be directly
assignable but can transformed into a valid choice.

This way we can add a "Create new" choice, create a new object once it’s
selected and return that newly created object as resolved choice.

refs #219

refs #219

refs #293

refs #219

Hosts shouldn’t be fetched all at once like it’s the case for stores
like categories and languages because there might be a lot of hosts in
the database.

This way users can enter the prompt value and just hit enter.

The container added a little spacing around it that sometimes caused
issues.

Users usually want to switch fields instead of indenting content.

refs #293

refs #291

refs aura#242
refs #282
refs #283

refs #290

refs #290

refs #290