Listen to platform color changes

[ebraminio]

Reading from macOS and Windows color accents happened on material-foundation/material-dynamic-color-flutter#42 and material-foundation/material-dynamic-color-flutter#43 and they work fine but they aren't responsive to OS changes. There are ways to get notified about OS changes and update colorings:

• Windows https://github.com/flutter/engine/pull/28131/files#diff-216c47499300810cf6eed53eca4e9cfe09aefa5b8c96b85f5a93e5caf3557378R61-R64 WM_DWMCOLORIZATIONCOLORCHANGED see also https://stackoverflow.com/q/65155419
• macOS https://github.com/flutter/engine/blob/2321e302428ffc0904e5f0050910511438e11de2/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm#L535-L555

What do you suggest here, to reimplement the logic here, or, make flutter engine to take those into account among their other offerings such as whether system is in dark mode. And how the Android one works, listening for onResume to reread from the platform?

[guidezpl]

I'm not sure since I'm not too familiar with the engine layer. You may face some resistance for adding a feature needed by a single package, unless you can justify other uses by the framework, or if implementing this logic here is infeasible. I'd create a flutter/flutter issue and get some feedback on the Discord.