This extracts the construction of the `SocketValueInferencer` out of
`SocketUsageInferencer`. This leads to better separation of concerns and gives
the caller more flexibility. In the future, I especially want to get information
about which group input values were required to determine the usage of other
group inputs. This might help with caching the inferenced values.
Pull Request: https://projects.blender.org/blender/blender/pulls/147352
Currently, `InferenceValue` contains either a primitive value or is in the
"unknown" state. Previously, all code had the assumption that when the value is
not unknown, it is a primitive value. However, that may not be true anymore when
we support inferencing through e.g. bundles and closures as those are not
"primitive". This assumption is removed now, non-primitive values have not been
added yet though.
Pull Request: https://projects.blender.org/blender/blender/pulls/145532
Value and usage inferencing can be done independently. Usage-inferencing uses
the value-inferencing but not the other way around. Extracting value-inferencing
makes the separation more clear and also simplifies potentially reusing the
value-inferencing code later on.
Pull Request: https://projects.blender.org/blender/blender/pulls/145492
