Prefer importing Jest globals

[dudeofawesome]

It would be preferred to import Jest methods such as describe & expect from @jest/globals rather than have them invisibly injected into the global scope.

Blockers:

• TypeScript declarations are not working when used with @jest/globals jest-community/jest-extended#674

  Jest extensions that we want to use only add their custom types to the global jest types, not to the types imported from @jest/globals. This will need to change before we can switch to imports.