Feature Request: Expose a method to change auth tenant at runtime

[joelmeaders]

Hey there, first of all, many thanks for this great project!

I'd like a way to change the auth tenant at runtime based on dynamic data. I know there's an injection token TENANT_ID but I'd like to support two use cases in particular.

1. A user could belong to multiple tenants and they would need to choose the tenant they wish to log into from a menu. Enter Email > Select Tenant > Enter Password > Log In
2. Set the tenant based on a navigation event from the Angular Router service.

For the second use case I can get it to partially work (without Router) via the DI token and the method below but it's static and won't react to route changes unless there's a full page reload.

const authTenantFactory = () =>
  window.location.pathname.split('/')[2] ?? null;