Generate .ng_deps.dart for a file with part directive.

[kegluneq]

part should not be carried over into the generated .ngDeps.dart file.

[kegluneq]

Handle the case where a type needed by an @Injectable is provided in a file included via a part directive.

Example:

foo.dart

library mylib;

part bar.dart

@Injectable
class Foo {
  Foo(Bar b);
}

bar.dart

part of mylib;

class Bar {}