Currently each node's position is stored in the coordinate space of
its parent. To find the location of a node on the canvas, we have to
apply the translation of each of its parents. Also, nodes have hidden
"offset" values used while transforming frame nodes. Together,
those made the system much more complicated than necessary,
and they made the Python API ineffective.
This commit removes usage of the offset values and moves nodes
to be stored in the "global" space of the node canvas. It also resolves
some weird behavior when resizing frame nodes, and fixes a few bugs.
The change is forward compatible, so we still write files with nodes in
the old parent-space format. In 5.0 the conversion when writing can be
removed. The existing Python API also stays the same. A new
"location_absolute" property gives node locations in global space,
and changing the old property also moves the child nodes of frames.
Resolves#92458, #72904.
Pull Request: https://projects.blender.org/blender/blender/pulls/131335
4bf34d9591