REPL: Issues with customElements registry

[Ocean-OS]

When working with Web Components at all in the Svelte REPL, to correctly update the preview, you have to reload the page. This is because a Custom Element can only be defined once, and since the REPL doesn't reload the iframe when the code changes, it causes errors to happen.
Reproduction

One possible remedy for this would be to check if the code uses custom elements, and if so, to reload the iframe on each code change.