Add a fields-aware implementation of the attribute proximity node.
The Source position is an implicit position field, but can be
connected with a position input node with alterations before use.
The target input and mode function the same as the original node.
Patch by Johnny Matthews with edits from Hans Goudey (@HooglyBoogly).
Differential Revision: https://developer.blender.org/D12635
9f0a3a99ab