Rework Uses statement ordering

Our current implementation of uses statements relies on a rather ugly hack to ensure statements are resolved in definition order, for example in case of:

container foo {
  uses bar;
  uses baz;
}
         
grouping baz {
  leaf baz {
    type string;
  }
}
         
grouping bar {
  leaf bar {
    type string;
  }
}

As the two uses statements are resolved in reverse order, we end up:

1. tracking effects of those statements separately
2. re-inline these effects when 'foo' is built in EffectiveStatementBase

Instead of this complicated tracking, we should be able to express a resolution dependency of 'uses baz' on 'uses bar', such that 'uses baz' is resolved only after 'uses bar' – which will naturally ensure that effectiveStatements are properly ordered.