A lot of files were missing copyright field in the header and
the Blender Foundation contributed to them in a sense of bug
fixing and general maintenance.
This change makes it explicit that those files are at least
partially copyrighted by the Blender Foundation.
Note that this does not make it so the Blender Foundation is
the only holder of the copyright in those files, and developers
who do not have a signed contract with the foundation still
hold the copyright as well.
Another aspect of this change is using SPDX format for the
header. We already used it for the license specification,
and now we state it for the copyright as well, following the
FAQ:
https://reuse.software/faq/
* Support bidirectional type lookups. E.g. finding the base type of a
field was supported, but not the other way around. This also removes
the todo in `get_vector_type`. To achieve this, types have to be
registered up-front.
* Separate `CPPType` from other "type traits". For example, previously
`ValueOrFieldCPPType` adds additional behavior on top of `CPPType`.
Previously, it was a subclass, now it just contains a reference to the
`CPPType` it corresponds to. This follows the composition-over-inheritance
idea. This makes it easier to have self-contained "type traits" without
having to put everything into `CPPType`.
Differential Revision: https://developer.blender.org/D16479
