Allow flutter run to work end-to-end with a UWP device.

Uses win32/ffi for the actual launch of the application, injected via
the native API class. This is structured to avoid a g3 dependency.

Install and amuid require powershell scripts for now.

Actually connecting to the observatory requires running a command in an
elevated prompt. Instructions are presented to the user if a terminal is
attached.

This is a rebased version of https://github.com/flutter/flutter/pull/79684
by @jonahwilliams, updated to remove `NativeApi` and replace is with calls
to `uwptool`.

Part of https://github.com/flutter/flutter/issues/82085