Temporal: Tests for Duration rounding fix & consolidation

[ptomato]

This PR contains test coverage for https://github.com/tc39/proposal-temporal/pull/2758 which was a normative change that reached consensus at the February 2024 TC39 meeting.

Note that we still expect some review comments from implementors on that PR, so these tests are currently marked as a draft.

[ptomato]

This is ready now.

[ptomato]

The few test files that are actually relevant to review, not just trivial adjustments, are:

• */dst-balancing-result.js
• */dst-rounding-result.js
• round/largestunit-smallestunit-combinations.js
• round/largestunit-smallestunit-combinations-relativeto.js
• total/dst-day-length.js
• total/no-dst-day-length.js
• total/total-of-each-unit.js
• total-of-each-unit-relativeto.js
• */roundingincrement-addition-out-of-range.js (added)

And note the change to weeks rounding in the various roundingmode-*.js tests. See https://github.com/tc39/proposal-temporal/issues/2728 for discussion on that topic.