Fixes https://github.com/flutter/flutter/issues/141827
Reland: https://dart-review.googlesource.com/c/sdk/+/346960 has rolled into g3, so the imports should now resolve in g3 as well.
> [!CAUTION]
> _Do NOT merge if "Google Testing" bot didn't run!_
Rolls the packages from https://github.com/dart-lang/native in the native assets implementation.
Most notable we're refactoring `package:native_assets_cli` for `build.dart` use.
Therefore, all imports to that package for Flutter/Dart should be to the implementation internals that are no longer visible for `build.dart` writers. Hence all the import updates.
No behavior in Flutter apps should change.
This PR also updates the template to use the latests version of `package:native_assets_cli` which no longer exposes all the implementation details.
Rolls the packages from https://github.com/dart-lang/native in the native assets implementation.
Most notable we're refactoring `package:native_assets_cli` for `build.dart` use.
Therefore, all imports to that package for Flutter/Dart should be to the implementation internals that are no longer visible for `build.dart` writers. Hence all the import updates.
No behavior in Flutter apps should change.
This PR also updates the template to use the latests version of `package:native_assets_cli` which no longer exposes all the implementation details.
I continued [my mission](https://github.com/flutter/flutter/pull/141431) to find as many typos as I could. This time it's a smaller set than before.
There is no need for issues since it's a typo fix.
Support for FFI calls with `@Native external` functions through Native assets on Windows. This enables bundling native code without any build-system boilerplate code.
For more info see:
* https://github.com/flutter/flutter/issues/129757
### Implementation details for Windows.
Mainly follows the design of https://github.com/flutter/flutter/pull/134031.
Specifically for Windows in this PR is the logic for finding the compiler `cl.exe` and environment variables that contain the paths to the Windows headers `vcvars.bat` based on `vswhere.exe`.
