fix: add `vrfDelay` as a `phase` return value for ongoing auctions to reflect VRFdelays in polkadot (#593)

* fix: update tests for auctions

* docs: auctions

* fix: add `delay` as a phase result

* fix: change delay to vrfDelay

* docs: update for vrfDelay

* fix: starting => startPeriod, ending => endPeriod

* docs: reflect startPeriod and endPeriod