Support version selection and bisecting in REPL

[Prinzhorn]

Describe the problem

The REPL at https://svelte-5-preview.vercel.app/ doesn't have a ?version= parameter. But even with the parameter in the OG REPL it is kind of painful to bisect to find a breaking version.

Describe the proposed solution

The Monaco Playground does this quite well (fun fact I gave them the Svelte REPL as an example microsoft/monaco-editor#3169). Not only can you select the version (not just full releases but also nightly builds) there's also a bisect mode that allows you to narrow down the breaking version fast (O(log n)).

1. Add a dropdown with versions, including builds between official releases (if possible, not sure if there's a concept of nightlies in Svelte)
2. Add a bisect mode

Monaco Playground dropdown

In bisect mode you can see the remaining number of version to be checked

Importance

would make my life easier