Blender Git Loki

XR: Controller Data Improvements

Provides two key improvements to runtime controller data.

1. Separates controller poses into two components, "grip" and "aim",
which are both required to accurately represent the controllers
without manual offsets.

Following their OpenXR definitions, the grip pose represents the
user's hand when holding the controller, and the aim pose represents
the controller's aiming source.

2. Runtime controller data is now stored as a dynamic array instead
of a fixed array. This makes the API/functionality more adaptable to
different systems.

Does not bring about any changes for users since only internal
runtime functionality is currently affected.

Reviewed By: Julian Eisel

Differential Revision: https://developer.blender.org/D12073