Support full clone html

[latot]

Rn, if we clone a html object, it will copy the references of the childs, so after clone something, rn the two objects will not be independents, would be good be able to clone an object and in case there is a pointer/reference, create a new one with the content.

[zannabianca1997]

I wouls also use this a lot! I'm using this library to do HTML layouts and replacing the slot note would replace it in the layout too