Support drag and drop of multiple images on a pict ring

[Dataflow_G]

Pict rings support drag and drop from File Explorer, but only for a single image. Filling a pict ring with more than a few images is a slow and potentially error prone process:

Drag and drop image from File Explorer into pict ring
Right-click pict ring -> Add item after
Drag and drop image from File Explorer into pict ring
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Right-click pict ring -> Add item after
Drag and drop image from File Explorer into pict ring

The idea is to allow dragging and dropping multiple images from File Explorer into a pict ring, and have it auto fill with each image as a new item.