Refactor: remove internal methods from Node

[marclaval]

These nodes are exposed to users and so they should expose useful methods. They could be pushed to a util class for example.

In scope: attachTo, attachAt, getInsertionNativeIndex, getAncestorWithNativeCreated, getAncestorDestroyed, getFirstCreatedChild, isTextContainer, isImageContainer, overrideTagName,
destroyNative

Out of scope: setProperty, setProperties, addEventListener, removeEventListener, fireEvent, focus, blur, dispatchCommand, getElementByTestId, querySelectorAll, querySelector, setText