chore(dbauth-mw): Refactor web side dbAuth creation

[dac09]

This PR changes how the webside auth is initialised, by removing the createMiddlewareAuth function, instead it just detects it internally.

For dbAuth this is what it will looks like:

import {
  createDbAuthClient,
  createAuth,
} from '@redwoodjs/auth-dbauth-web'

const dbAuthClient = createDbAuthClient({
  middleware: true,
})

// Internally we know to use the middleware version of the client
// because middleware is set to true above!
export const { AuthProvider, useAuth } = createAuth(dbAuthClient)

For other auth providers we are going to export a similar looking function:

import { createAuth, createSupabaseAuthClient } from '@redwoodjs/auth-supabase-web'

// This function is new, and just wraps creating supabase👇
const supabaseClient = createSupabaseAuthClient({
  supabaseUrl: process.env.SUPABASE_URL || '',
  supabaseKey: process.env.SUPABASE_KEY || '',
  middleware: true
})

export const { AuthProvider, useAuth } = createAuth(supabaseClient)

This also means our users won't need to change where supabase client is imported from, for example.

[dac09]

@dthyresson just tagging you here for visibility. We already discussed and agreed on this yesterday :)