Promotions should be sorted lexicographically

[hiddeco]

The ~~UI~~ API server appears to order Promotions for a Stage by their Phase and creation timestamp. However, as the creation timestamp does not include nanoseconds, this approach will fail when multiple Promotions are (programmatically) created within a short period.

To address this issue, it should use the ULID in the Promotion name, which allows it to be lexicographically sorted beyond the creation timestamp of the Promotion.