When creating nodes by dragging a link, it can be convenient to
transfer values from input socket. For reference values, like images,
this may be necessary to avoid unnecessary data-block users. This
patch starts adding such a system. At this moment this only makes sense
for one node (Image Input), but this can be extended to work with other
reference types, different non-reference types and support auto-casting
(if a float is transferred to the Integer Input node).
See task: https://projects.blender.org/blender/blender/issues/102854
Original patch: https://archive.blender.org/developer/D16735
Pull Request: https://projects.blender.org/blender/blender/pulls/105972
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