Svelte 5 Upgrade

[joshnuss]

• [x] Convert state management to Runes
• [x] Remove svelte/legacy
• [x] Remove createEventDispatcher and replace on:event -> onevent
• [x] Convert code to TypeScript
• [x] Update docs
• [x] Ensure All wrapper <div>'s use CSS display: contents
• [x] Simplify Props types, use Stripe's option types directly when possible.
• [x] Use onMount for initializing components
• [ ] Use $effect() to sync prop changes with Stripe via element.update()
• [ ] Check each component to confirm is supports of all Stripe's attributes and events
• [ ] Add <Elements.Deferred> component for creating payment intent later.
• [ ] Lint and prettify
• [ ] Manually test all components
• [ ] Create changelog of breaking changes