This patch adds support for 2D and 4D vector sockets. The default value
structure for vectors was extended to include a new dimensions input,
which can be 2, 3, or 4. The default value was also extended to be a
float4, but only some of its components might be used depending on the
dimensions members.
Each vector subtype now has three variants ending with 2D or 4D as a
prefix depending on its dimensions, and the 2D/4D prefix was taken into
account for the socket type RNA enum functions.
All node systems currently always treat the vectors as 3D, but support
for it in the compositor will shortly follow in another patch.
Depends on #138805.
Pull Request: https://projects.blender.org/blender/blender/pulls/138824
02a95d088e