Allow users to be assigned to multiple workspaces of Port

[canny[bot]]

Sometimes there is a need to create multiple Port "Workspaces", for example, for staging and prod versions of Port.

We would like to add the ability to create several workspaces to an organization and to be able to easily switch between them via Port's UI.

https://port.canny.io/admin/board/ideas/p/allow-users-to-be-assigned-to-multiple-workspaces-of-port