add csrf helpers

[huseeiin]

Describe The Problem To Be Solved

its highly important to add csrf protection to forms and any mutation http verb (like POST, UPDATE, DELETE, etc.) in solid.js case, server functions.

Suggest A Solution

i think it'd be cool to add csrf generate and verify functions similar to Bun.CSRF: https://x.com/jarredsumner/status/1899194018480988259

[atk]

That's a pretty great idea. Thanks!