Blender Git Loki

Blenlib: introduce a UUID type

Add `BLI_uuid` and `DNA_uuid_types.h` with a UUID implementation
following RFC4122 (https://datatracker.ietf.org/doc/html/rfc4122.html).

The following features are implemented:
- A struct of 128 bits that can be used in DNA definitions.
- Generation of version 4 UUIDs, that is, purely random ones.
- UUID equality function.
- String to UUID and UUID to string conversion functions that are
compatible with RFC4122.
- C++ stream operator that outputs the UUID as string.

This UUID will be used by the asset system, to uniquely identify asset
catalogs.

Reviewed By: Severin, jacqueslucke

Differential Revision: https://developer.blender.org/D12475