Custom Status should not default to Done

When using the status "Blocked", a test case execution is considered "Done". We most often use "Blocked" as a temporary status to note when something's start or work is impeded, however, it instead gives the team credit for complete work. We introduced a custom status instead, but all custom statuses are also considered "Done". Zephyr Scale should allow us to indicate whether a custom status is "Done" or not.