Adds a Shape Method parameter to the UV Pack Islands node, enabling
artists to choose between faster packing and more efficient space
utilization.
Those are the three shape method options:
* Bounding Box: Fastest, less efficient space usage
* Convex Hull: Balanced performance and efficiency
* Exact Shape: Optimal packing, higher computational cost
This change consolidates arguments in `uv_parametrizer_pack()`. Now it
accept ` UVPackIsland_Params` instead of many different separate options.
This also makes it easier to expose more options in the future.
Pull Request: https://projects.blender.org/blender/blender/pulls/139110
aced349e3d