In this PR
- updateWorkspaceMemberRole api was changed to stop allowing null as a
valid value for roleId. it is not possible anymore to just unassign a
role from a user. instead it is only possible to assign a different role
to a user, which will unassign them from their previous role. For this
reason in the FE the bins icons next to the workspaceMember on a role
page were removed
- updateWorkspaceMemberRole will throw if a user attempts to update
their own role
- tests tests tests!
