Object-> Snap-> selection to cursor (child of)

Snapping a selection to the cursor is a wonderful feature. But it doesn't really work if the object one is snapping to the cursor has a "child of" constrain. (instead it goes flying off somewhere into space, for logical reasons.)

Similar to the "selection to cursor (keep offset)" we make another snapping option: "selection to cursor (child of)"

This option figures out the cursor's location from the perspective of the parent in the child of constraint. This local view of our cursor then becomes the global position of our object, since then it aligns with the cursor after being influenced by the child of constraint. (technically a tiny bit more complex than this because the child of constraint also handle an offset thanks to the "set inverse" feature.)

How this works if one has multiple child of constraints active at once is a logical puzzle I won't ponder over, same story for an influence between 0 and 1, lets at least have the option for 1 child of constraint at an influence of 1, since that is trivial. Preferably only consider the active child of constraint, in cases where we move between multiple such constraints throughout an animation.

In the end we can then snap an object to the cursor when influenced by the child of constraint.

If we want to further dive into also having a "selection to cursor (child of, keep offset)" is debatable.