[front] feat: update invitation flow to support WorkOS

[aubin-tchoi]

Description

• Closes https://github.com/dust-tt/tasks/issues/2992.
• This PR handles the invitation flow when logging and signing up using WorkOS.
• API reference: https://workos.com/docs/reference/user-management/authentication/get-authorization-url.

Tests

Local:

• In a non-SSO setup: invite a user by email, click on the link in the email, go through the signup flow and check that we end up in the correct workspace instead of creating one.

Risk

• TBC

Deploy Plan

• Deploy front.

[dust-agent]

Found coding rule violations that need to be addressed.

[tdraier]

Let's wait until we correctly handle login switch before merging

[aubin-tchoi]

as per IRL: @tdraier cleaned up the FF so we're good to merge 🙏🏻