[NUI] Fix to require Layout to fit to children or fill to parent

[NUI] Fix to require Layout to fit to children or fill to parent

This patch is necessary to the following patch.
"[NUI] Deprecate ResizePolicyType"

It is impossible that LayoutParamPolicies.WrapContent supports both
ResizePolicyType.UseNaturalSize and FitToChildren.

Therefore, LayoutParamPolicies.WrapContent does not support
ResizePolicyType.UseNaturalSize nor FitToChildren.
Instead, LayoutParamPolicies.WrapContent makes View fit to its children
only if the View sets its Layout.

In the same way, LayoutParamPolicies.MatchParent does not support
ResizePolicyType.FillToParent.
Instead, LayoutParamPolicies.MatchParent makes View fill to its parent
only if the View sets its Layout.

If View uses LayoutParamPolicies.WrapContent or MatchParent while it
does not set its Layout, then the View does not fit to its children nor
fill to its parent.
Instead, ResizePolicyType.UseNaturalSize is supported by default.