What would you like to be added:

When an item T implements IKeyEquatable<T>, we should be able to do await ListState.UpdateItemAsync(oldT, newT).

Currently we need to do something like : ListState.UpdateAllAsync(t => t.KeyEquals(newT), newT);

Why is this needed:

Simplicity

For which Platform:

• iOS
• Android
• WebAssembly
• WebAssembly renders for Xamarin.Forms
• Windows
• Build tasks

Anything else we need to know?