fix(jqLite): correctly dealoc svg elements in IE

SVG elements in IE don't have a `.children` but only `.childNodes` so it broke.
We started using `.children` for perf in e35abc9d2fac0471cbe8089dc0e33a72b8029ada.

This also acts as a perf improvements, since
`getElementsByTagName` is faster than traversing the tree.

Related #8075