Add ability to use multiple Facets of the same type#1

e.g. ``` <Entity> <Image src="https://example.com/img1.jpg" width="100" height="150" position={[0, 0, 0]} /> <Image src="https://example.com/img2.jpg" width="10" height="10" position={[90, 10, 0]} /> <ThreeView> <mesh></mesh> </ThreeView> </Entity> ``` Will require a way to query for multiple facets, e.g. ``` query.loop([ThreeView, [Image]], (e, [view, image]) => { }); ``` Or potentially, Facet could inherit from `React.Component` to allow children? ``` <ImageFacet> <image one> <image two> </ImageFacet> ```