[request] pass off d9d9 to gallum-nine if the driver supports it.

[Aerocatia]

It should be reasonably possible to have this library optionally use Mesa's native d3d9 implementation if is is available.
Using gallium nine is often more performant than translating d3d9 to Vulkan, however this is hampered by not being supported on anything other than the open source drivers.

There is an opportunity here to have this library transparently use it if the user is able to. These performance gains are worth the trouble, especially on late d3d9 renderers, Valve's own games should benefit from this.