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/modules/auth/sign-in-up/hooks/useWorkspaceFromInviteHash.ts

@@ -4,8 +4,13 @@ import { useGetWorkspaceFromInviteHashQuery } from '~/generated/graphql';
 
 export const useWorkspaceFromInviteHash = () => {
   const workspaceInviteHash = useParams().workspaceInviteHash;
-  const { data: workspaceFromInviteHash } = useGetWorkspaceFromInviteHashQuery({
-    variables: { inviteHash: workspaceInviteHash || '' },
-  });
-  return workspaceFromInviteHash?.findWorkspaceFromInviteHash;
+  const { data: workspaceFromInviteHash, loading } =
+    useGetWorkspaceFromInviteHashQuery({
+      variables: { inviteHash: workspaceInviteHash || '' },
+    });
+  return {
+    workspace: workspaceFromInviteHash?.findWorkspaceFromInviteHash,
+    workspaceInviteHash,
+    loading,
+  };
 };