Incorporate leptosfmt into CI

[LesnyRumcajs]

Summary

There's a tool for better formatting the embedded HTML code (everything inside view!) https://github.com/bram209/leptosfmt

It'd be great to incorporate it into CI and apply across the codebase. Bonus points if we won't have to re-compile leptosfmt from scratch on every commit, which is quite wasteful.

Completion Criteria

• Incorporate leptosfmt into CI,
• Apply changes from leptosfmt.

Additional Links & Resources

[LesnyRumcajs]

I ended up creating one myself over the weekend because I couldn't stand the lack of it in the leptos ecosystem. 🐺 https://github.com/LesnyRumcajs/leptosfmt-action