Add HDR support

[shinyquagsire23]

Adds HDR support by changing compositing framebuffer formats to DXGI_FORMAT_R16G16B16A16_FLOAT (conditionally). Currently, it only works with Windows NVENC.

Tested and working on:

• RTX 4090
• Apple Vision Pro
• Quest 3
• Quest Pro
• Pico 4

Other notes:

• Has to convert to DXGI_FORMAT_P010 and DXGI_FORMAT_NV12 in an extra shader pass, because NVENC is really picky about texture inputs for NV_ENC_BUFFER_FORMAT_YUV420_10BIT and NV_ENC_BUFFER_FORMAT_NV12 and the other 10-bit ones didn't really work.
• There's a bit of a hack in the YUV pipeline: The Y and UV components are attached to the shader as two output textures, because that's just how it works. But for some ungodly reason, DirectX 11 doesn't raster the entire Y plane unless it is the only texture view attached. If there's two texture views attached, it renders exactly 1/4 of the Y plane. Feels like a driver bug tbh. So there's a hack for that.
• HDR uses BT.2020 instead of BT.709
• The transfer characteristic for NVENC was changed to sRGB. I don't think it matters except for video players that don't know the underlying texture is sRGB.
• The frame render shader has an extra 2 cases for sRGB correction, only active for HDR rendering of sRGB games or SDR rendering of HDR games.
• The frame render shader also has an optional clamp() to remove extended range color (ie, so HDR/float16 games will reduce banding but not require extra tonemapping, which we don't do, to look correct)
• The Android client was modified to composite to float16, which reduces banding on Quest 3, and displays extended gamut color on Quest Pro (for some reason it does not reduce banding on Quest Pro??)
• The Android client also had a minor bugfix as a side-effect: my limited range bugfix was also applied erroneously to the lobby. It had to be turned off for HDR/BT.2020 decoded streams.

Bugs:

• The YUV render target seems to have a different issue on AMD GPUs, and renders the UV channel incorrectly. It's possible DirectX requires some kind of extra alignment besides the framebuffer size being even. The good news is that my AMD codec patches seem to work, so it's just the P010 texture.

Shaders were compiled with:

"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\fxc.exe" /T ps_5_0 /O3 /Qstrip_reflect /Qstrip_debug /Qstrip_priv /Qstrip_rootsignature /Fo alvr\server\cpp\platform\win32\ColorCorrectionPixelShader.cso alvr\server\cpp\alvr_server\shader\ColorCorrectionPixelShader.hlsl
"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\fxc.exe" /E PS /T ps_5_0 /O3 /Qstrip_reflect /Qstrip_debug /Qstrip_priv /Qstrip_rootsignature /Fo alvr\server\cpp\platform\win32\FrameRenderPS.cso alvr\server\cpp\alvr_server\shader\FrameRender.fx
"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\fxc.exe" /T ps_5_0 /O3 /Qstrip_reflect /Qstrip_debug /Qstrip_priv /Qstrip_rootsignature /Fo alvr\server\cpp\platform\win32\CompressAxisAlignedPixelShader.cso alvr\server\cpp\alvr_server\shader\CompressAxisAlignedPixelShader.hlsl

"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\fxc.exe" /T ps_5_0 /O3 /Qstrip_reflect /Qstrip_debug /Qstrip_priv /Qstrip_rootsignature /Fo alvr\server\cpp\platform\win32\rgbtoyuv420.cso alvr\server\cpp\alvr_server\shader\rgbtoyuv420.hlsl

"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\fxc.exe" /T vs_5_0 /O3 /Qstrip_reflect /Qstrip_debug /Qstrip_priv /Qstrip_rootsignature /Fo alvr\server\cpp\platform\win32\QuadVertexShader.cso "alvr\server\cpp\platform\win32\d3d-render-utils\QuadVertexShader.hlsl"
"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\fxc.exe" /E VS /T vs_5_0 /O3 /Qstrip_reflect /Qstrip_debug /Qstrip_priv /Qstrip_rootsignature /Fo alvr\server\cpp\platform\win32\FrameRenderVS.cso alvr\server\cpp\alvr_server\shader\FrameRender.fx

[barnabwhy]

Testing this on Windows + AMD and my Quest 3, it does not seem to be working very well :(

h264 + HDR:

[zmerp]

Style-wise, looks ok to to me.