feat: Add signup and sign-in with EOA

[dylsteck]

Description

Add components & hooks for signup and sign-in with an EOA. This will be compatible with(and come with examples for) Dynamic, Privy, and RainbowKit out of the box, with future support for embedded wallets to further improve the signup/sign-in UX.

Progress

• Signups are about ~90% done, you can see and read more about this integration's progress here
  • Need to fix an error I'm getting when calling the Bundler contract, then I can patch up styling and add the components/hooks to the farcasterkit package

[dylsteck]

note: two other follow-up features to the auth stack after these are complete would be Farcaster Connect(account verification only, coming soon from Warpcast) and Warpcast Sign-In(traditional deep-linked sign-in without an EOA)

[dylsteck]

Adding all open issues to my working branch(auth)'s README for now