add create index API as an async job

[pdowler]

this proposed solution is for a parameter-style UWS job that fits the current DAL landscape

[mbtaylor]

405 is not likely to be an appropriate response here - it's only correct if this resource exists but does not support any POST requests (and would have to be accompanied by an Allow header giving a list of HTTP methods that are supported for that resource) - see RFC9110 sec 15.5.6.

[pdowler]

Do you think that a 404 when probing for an optional endpoint is sufficient for the client?

This is a UWS job list endpoint so I agree that optional means it is either there or not, but technically the possibility of a 405 is really up to UWS. That's kind of the awkward thing about UWS and OpenAPI: the job description (params) have to be here but the response can come from the UWS component.

[brianmajor]

I guess the job list (GET) would also have to return a 404. Seems natural to me because a 1.1 TAP implementation would return a 404.