feat(auth): Implement Supabase Auth Middleware

[dthyresson]

Addresses https://github.com/orgs/redwoodjs/projects/18/views/1?pane=issue&itemId=59186951

• feat(auth): Implement Supabase Auth Middleware (feat(auth): Implement Supabase Auth Middleware #10499) by @dthyresson, @dac09

Implement Supabase Auth Middleware to authenticate server-side requests.

• Adds middleware to the Supabase auth-providers package.
• createSupabaseAuthMiddleware is responsible for authenticating Supabase requests
• It does so by checking if the request has a supabase auth-provider header, and then uses the authDecoder to verify the session cookie using the Supabase ServerAuthClient and returning a decoded access token -- or throwing an exception if the session cookie is invalid
• Once the middleware has the decoded JWT, it hands that to the provided getCurrentUser from he user's project to return the information about authenticated user
• Lastly, it sets serverAuthContext with user and metadata info to know the request isAuthenticated
• If the session is invalid or the cookie tampered with such that the access token cannot be verified, serverAuthContext is cleared as are the auth provider and Supabase cookies

[dac09]

LGTM!