* Add missing test descriptions
* Fix async tests that expect a rejection
These tests expected the function under test to return a rejected
promise, and had assertions to be run in the `catch` clause. However,
the tests would still pass if the function didn't reject, with
the assertions never being run.
The tests have been updated to fail if the function doesn't throw.
* Handle ignored promise rejection
In the case where `forceUpdateMetamaskState` rejects, the function
`setSeedPhraseBackedUp` would never resolve. It has been updated to
pass along the rejection instead.
* Return after rejecting promise in action
A few actions would continue after encountering an error, resulting in
errors being compounded. Instead all actions will now return after
encountering an error (which it looks like was the intention in these
cases anyway).
