Fix elm breaking when dom nodes are modified POC

fix-elm-breaking-on-moving-elements.js

// run here in iframe scope for demo: https://elm-lang.org/examples/buttons

const vdomParent = document.querySelector('div')
const vdomChild = document.querySelector('div div')
const slot = document.body

console.log(vdomParent.childNodes)
console.log('child', vdomParent.childNodes[0])

const applySlots = () => {
    const proxyChild = document.createElement('slot-replaced')
    proxyChild.innerHTML = "SLOT"
    vdomParent.replaceChild(proxyChild, vdomChild)
    console.log('child after move', vdomParent.childNodes[0])
    slot.appendChild(vdomChild)

    vdomParent.childNodes_ = vdomParent.childNodes
    Object.defineProperty(vdomParent, 'childNodes', {get (a, b) {
        return (Array.from(this.childNodes_).map(ch => ch.tagName == "SLOT-REPLACED"? vdomChild : ch))
        return this.childNodes_
    }, set (v) {
        this.childNodes_ = v
    }})
}
applySlots()

console.log('children with new getter', vdomParent.childNodes)