Answer named questions about an IVR caller

Posted by an IVR widget that wants to know something about the caller (GE-3316).

camelCase like the sibling IVR schemas. Every field is optional on purpose: refusing a request over a missing field would strand the call. masterRecordId is a plain string, not a UUID type, so a malformed id yields "no case" rather than a 422 the flow cannot recover from.

facts names what the widget wants. Only those are computed, so a widget that needs nothing asks for nothing and pays for no query; omitted, null or empty means none.

The requested facts as "true"/"false" strings (the convention of isOpen and isHoliday).

A fact is null when it could not be determined: null is not "false", so the flow can tell "no" from "could not tell". details holds what a fact names, by fact name (for hasOpenWelcomeCase, whether the case owner holds the TTEC skill as ownerHasTtecSkill "true"/"false", and their Twilio workerSid, an empty string when there is no one). Names that were asked for and do not exist are in unknownFacts.