Improve duplicate item API mutation to also change values & group

Improve the duplicate_item mutation to allow specifying a new group, and a column_values key for values to change.

This would permit a single mutation to duplicate a new item with only specific column changes in an arbitrary group. While it can be accomplished with multiple mutations, doing it in a single will reduce sequential triggering of automations and overall platform load.

Thank you @anon29275264 for the request!!