What would you like to be added:

Currently ReturnType does not support all targets. The Uno.UI built-in TextBoxExtensions.InputReturnType is available across all targets. The Toolkit API can use it directly and avoid platform-specifics.

Why is this needed:

Support of all targets.

For which Platform:

• WebAssembly
• Android
• iOS
• macOS (AppKit)
• Mac Catalyst
• Skia
  • WPF
  • GTK (Linux)
  • Linux Framebuffer
  • Tizen
• Windows

Anything else we need to know?