add HDR support (addresses #121)

[EndlesslyFlowering]

addresses #121

HDR output needs flip model, so this PR forces the flip model when HDR is activated (user setting is not touched).

Missing:

• check if current display supports HDR
• check if the Windows version supports IDXGISwapChain3 and therefore SetColorSpace1 (https://learn.microsoft.com/en-us/windows/win32/api/dxgi1_4/nf-dxgi1_4-idxgiswapchain3-setcolorspace1).