Refactor: use replaceChildren pattern to create lists

[marcustyphoon]

Description

As noted in #677 (comment), there are a number of places where we could use replaceChildren to update a list's contents in the DOM all in one go, rather than emptying it, (often) waiting asynchronously for a preference fetch, then adding the desired elements in one-by-one.

The meaningful behavior change resulting from this is that if the code throws or the preference fetch stalls, the old elements are left in place rather than the list becoming blank, which may be a more confusing failure mode.

Testing steps