[NUI] Make ReleaseSwigCPtr didn't check HasBody()

[NUI] Make ReleaseSwigCPtr didn't check HasBody()

After PR #4892 `HasBody()` can be false in `ReleaseSwigCPtr`.
So, some class who check double-released might not release
native memory. It might occure some leak.

This patch make them to check `Disposed` instead of `HasBody()`.

+

Clean up some codes of `ReleaseSwigCPtr`.

TODO : Also need to check `Disposable.Dispose` function

TODO : Need to check third-party library implementation who use
their custom `ReleaseSwigCPtr`

Signed-off-by: Eunki Hong <eunkiki.hong@samsung.com>