refs: https://github.com/TryGhost/Toolbox/issues/595
We're rolling out new rules around the node assert library, the first of which is enforcing the use of assert/strict. This means we don't need to use the strict version of methods, as the standard version will work that way by default.
This caught some gotchas in our existing usage of assert where the lack of strict mode had unexpected results:
- Url matching needs to be done on `url.href` see aa58b354a4
- Null and undefined are not the same thing, there were a few cases of this being confused
- Particularly questionable changes in [PostExporter tests](c1a468744b) tracked [here](https://github.com/TryGhost/Team/issues/3505).
- A typo see eaac9c293a
Moving forward, using assert strict should help us to catch unexpected behaviour, particularly around nulls and undefineds during implementation.
refs https://github.com/TryGhost/Team/issues/3010
- Having all possible values in within single packages will make it easier to look for "source of truth" and is more maintainable rather than having values scattered all over the codebase
refs https://github.com/TryGhost/Team/issues/3051
- The filter was not working properly when there was no logged in member, but the announcement filter was set to "paid_members" only
