This moves the common camera setup code out of the individual drivers,
and completely removes vup/vright/vpn from the non-software renderers.
This has highlighted the craziness around AngleVectors with it putting
+X forward, -Y right and +Z up. The main issue with this is it requires
a 90 degree pre-rotation about the Z axis to get the camera pointing in
the right direction, and that's for the native sw renderer (vulkan needs
a 90 degree pre-rotation about X, and gl and glsl need to invert an
axis, too), though at least it's just a matrix swizzle and vector
negation. However, it does mean the camera matrices can't be used
directly.
Also rename vpn to vfwd (still abbreviated, but fwd is much clearer in
meaning (to me, at least) than pn (plane normal, I guess, but which
way?)).
This needed changing Vulkan_CreatePipeline to
Vulkan_CreateGraphicsPipeline for consistency (and parsing the
difference from a plist seemed... not worth thinking about).
It turned out the bindless approach wouldn't work too well for my design
of the sprite objects, but I don't think that's a big issue at this
stage (and it seems bindless is causing problems for brush/alias
rendering via renderdoc and on my versa pro). However, I have figured
out how to make effective use of descriptor sets (finally :P).
The actual normal still needs checking, but the sprites are currently
unlit so not an issue at this stage.
