- #6648
- a different take on #4871
- `DateTime` can also round-trip `DateTimeKind.UTC` with `[DataType("datetimeoffset")]` or `[UIHint("datetimeoffset")]`
- since they're now handled differently by default, add more `DateTime` tests
- expand tests involving `Html5DateRenderingMode.CurrentCulture`
nits: make VS-suggested changes to files updated in this PR