bbrk24

My concern with resizable spinners is that I'll often do something like ```swift HStack { Spacer() ProgressView() Spacer() } ``` to center a spinner within a larger view. Would this...

It doesn't need to be done now (I could do this in a future PR), but maybe some code could be added to UIKitBackend to change the spinner between `.medium`...

The thought just occurred to me to observe [NSSystemTimeZoneDidChange](https://developer.apple.com/documentation/foundation/nsnotification/name-swift.struct/nssystemtimezonedidchange) to properly redraw views that use `@Environment(\.timeZone)`, but I'm unsure how that would work, and regardless I don't see an equivalent...

Right, I'll go see if I can get that to work in UIKitBackend and AppKitBackend first, and then maybe the other backends. I don't think it'll necessarily work on Linux...

Marking this as draft because UIDatePicker (at least on iOS 17) completely misbehaves if the user changes the time zone in settings

> Now that the DatePicker example is relatively simple, I reckon it could make sense to merge it into ControlsExample. Done, and added a `#if` so that it can still...