[Windows] Better document TitleBar customizations with windows and possible provide samples

[PureWeen]

Description

We get about 2 issues a month around confusions with customizing the WinUI Titlebar

https://github.com/dotnet/maui/issues/20976#issuecomment-1977173364

WinUI drastically changed the TitleBar implementation between 1.2 and 1.3 which led to some change in behaviors.

It would be good to document how you customize the MAUI titlebar in our official docs and possible provide samples into maui-samples in order to help folks better navigate custom title bar implementations.

[jonmdev]

Is there any way to make the TitleBar solid color with just C#? A method was given here for xaml but I don't use any xaml anywhere in my projects.

Thanks for any guidance. Sorry for any redundancy.

https://github.com/dotnet/maui/issues/20976