Add React Hook Form and Zod

[robines]

The goal of this PR is to add the building blocks required to see if we can replace SamfForm with something more stable and easy to use. This uses React Hook Form and Zod, which are very actively developed projects. React Hook Forms adds React hooks for form management, while Zod adds schema validation with static type inference.

Notable changes:

• Add form components from shadcn/ui (slightly adjusted)
  • This adds wrappers around React Hook Forms. See the benefits under "Features" on the page linked above
• Add Zod error message translations with zod-i18n
• Add example usage to Components page.
  • Relevant file to look at is ExampleForm.tsx
  • This also adds reusable Zod schema fields for username and password. More to come

Styling is NOT finalized.

Caveats:

• Automatic form error message translations work, but only on render. Meaning if you get an error message, then change langauge, the already-rendered messages won't be translated until you force them to rerender

[Snorre98]

Docs pls

[Snorre98]

For en fyr! For en PR!