Refactor onboarding user vars to be absent when user is fully onboarded (#6531)

In this PR:
- take feedbacks from: https://github.com/twentyhq/twenty/pull/6530 /
https://github.com/twentyhq/twenty/pull/6529 /
https://github.com/twentyhq/twenty/pull/6526 /
https://github.com/twentyhq/twenty/pull/6512
- refactor onboarding uservars to be absent when the user is fully
onboarded: isStepComplete ==> isStepIncomplete
- introduce a new workspace.activationStatus: CREATION_ONGOING

I'm retesting the whole flow:
- with/without BILLING
- sign in with/without SSO
- sign up with/without SSO
- another workspaceMembers join the team
- subscriptionCanceled
- access to billingPortal

packages/twenty-server/src/engine/core-modules/jwt/services/jwt-wrapper.service.ts

@@ -7,7 +7,12 @@ import * as jwt from 'jsonwebtoken';
 export class JwtWrapperService {
   constructor(private readonly jwtService: JwtService) {}
 
-  sign(payload: string, options?: JwtSignOptions): string {
+  sign(payload: string | object, options?: JwtSignOptions): string {
+    // Typescript does not handle well the overloads of the sign method, helping it a little bit
+    if (typeof payload === 'object') {
+      return this.jwtService.sign(payload, options);
+    }
+
     return this.jwtService.sign(payload, options);
   }