4689 multi workspace i should be able to accept an invite if im already logged in (#5454)

- split signInUp to separate Invitation from signInUp
- update redirection logic
- add a resolver for userWorkspace
- add a mutation to add a user to a workspace
- authorize /invite/hash while loggedIn
- add a button to join a workspace

### Base functionnality

https://github.com/twentyhq/twenty/assets/29927851/a1075a4e-a2af-4184-aa3e-e163711277a1

### Error handling

https://github.com/twentyhq/twenty/assets/29927851/1bdd78ce-933a-4860-a87a-3f1f7bda389e

packages/twenty-front/src/pages/auth/SignInUp.tsx

@@ -1,3 +1,43 @@
-import { SignInUpForm } from '../../modules/auth/sign-in-up/components/SignInUpForm';
+import { useMemo } from 'react';
+import { useRecoilValue } from 'recoil';
 
-export const SignInUp = () => <SignInUpForm />;
+import { Title } from '@/auth/components/Title';
+import { SignInUpForm } from '@/auth/sign-in-up/components/SignInUpForm';
+import {
+  SignInUpMode,
+  SignInUpStep,
+  useSignInUp,
+} from '@/auth/sign-in-up/hooks/useSignInUp';
+import { useSignInUpForm } from '@/auth/sign-in-up/hooks/useSignInUpForm';
+import { currentWorkspaceState } from '@/auth/states/currentWorkspaceState';
+import { isDefined } from '~/utils/isDefined';
+
+export const SignInUp = () => {
+  const { form } = useSignInUpForm();
+  const currentWorkspace = useRecoilValue(currentWorkspaceState);
+
+  const { signInUpStep, signInUpMode } = useSignInUp(form);
+
+  const title = useMemo(() => {
+    if (
+      signInUpStep === SignInUpStep.Init ||
+      signInUpStep === SignInUpStep.Email
+    ) {
+      return 'Welcome to Twenty';
+    }
+    return signInUpMode === SignInUpMode.SignIn
+      ? 'Sign in to Twenty'
+      : 'Sign up to Twenty';
+  }, [signInUpMode, signInUpStep]);
+
+  if (isDefined(currentWorkspace)) {
+    return <></>;
+  }
+
+  return (
+    <>
+      <Title animate>{title}</Title>
+      <SignInUpForm />
+    </>
+  );
+};