Set per-test expected duration

[kadler]

The default "slow" time for tests is 75ms. Any test taking longer than that will be marked slow. Our functional toolkit tests take 1000-4000s, however, so they are all marked "slow". We should adjust each test case to determine what a proper slow value is for it and mark it appropriately.

https://mochajs.org/#test-duration

[kadler]

Blocked by #200

[github-actions]

👋 Hi! This issue has been marked stale due to inactivity. If no further activity occurs, it will automatically be closed.