Open questions about swap chain formats #1231

• 1. How sRGB works exactly (can browser always choose between non-srgb and srgb formats? does the app get to have a say; e.g. if they really want srgb, but they want to choose the most optimal between rgba8-srgb and bgra8-srgb, can they?)
• 2. HDR and float16 etc
• 3. getSwapChainPreferredFormat with a list of "formats the app can understand"
• 4. How this interacts with CanvasColorEncodingEnum, if we expose both
• 5. How to expose display-specific preferred formats that could change when a window is moved between displays

Originally posted by @kainino0x in #1185 (comment)