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-server/src/engine/core-modules/auth/auth.resolver.ts

@@ -27,7 +27,6 @@ import { EmailPasswordResetLink } from 'src/engine/core-modules/auth/dto/email-p
 import { InvalidatePassword } from 'src/engine/core-modules/auth/dto/invalidate-password.entity';
 import { EmailPasswordResetLinkInput } from 'src/engine/core-modules/auth/dto/email-password-reset-link.input';
 import { GenerateJwtInput } from 'src/engine/core-modules/auth/dto/generate-jwt.input';
-import { UserWorkspaceService } from 'src/engine/core-modules/user-workspace/user-workspace.service';
 import { AuthorizeApp } from 'src/engine/core-modules/auth/dto/authorize-app.entity';
 import { AuthorizeAppInput } from 'src/engine/core-modules/auth/dto/authorize-app.input';
 import { ExchangeAuthCodeInput } from 'src/engine/core-modules/auth/dto/exchange-auth-code.input';
@@ -56,7 +55,6 @@ export class AuthResolver {
     private authService: AuthService,
     private tokenService: TokenService,
     private userService: UserService,
-    private userWorkspaceService: UserWorkspaceService,
   ) {}
 
   @UseGuards(CaptchaGuard)

packages/twenty-server/src/engine/core-modules/auth/services/sign-in-up.service.ts

@@ -150,26 +150,10 @@ export class SignInUpService {
     );
 
     if (existingUser) {
-      const userWorkspaceExists =
-        await this.userWorkspaceService.checkUserWorkspaceExists(
-          existingUser.id,
-          workspace.id,
-        );
-
-      if (!userWorkspaceExists) {
-        await this.userWorkspaceService.create(existingUser.id, workspace.id);
-
-        await this.userWorkspaceService.createWorkspaceMember(
-          workspace.id,
-          existingUser,
-        );
-      }
-
-      const updatedUser = await this.userRepository.save({
-        id: existingUser.id,
-        defaultWorkspace: workspace,
-        updatedAt: new Date().toISOString(),
-      });
+      const updatedUser = await this.userWorkspaceService.addUserToWorkspace(
+        existingUser,
+        workspace,
+      );
 
       return Object.assign(existingUser, updatedUser);
     }