feat: adds additional operations for path item object

[baywet]

fixes #1747

[ralfhandl]

Could you please add a failing test case trying to use "GET" as an additional operation?

[baywet]

Could you please add a failing test case trying to use "GET" as an additional operation?

done. I added POST instead to make it clear that it's not just a collision with what's defined in the document, but rather a matter of "where things should go".

[handrews]

@baywet @kevinswiber I did not see a reply in the issue to my idea that we include query among the special-cased fields rather than relegating it to additionalOperations, since it is on the verge of becoming an IANA-registered general-purpose (non-WebDAV) HTTP method. I would prefer that approach.

[baywet]

@baywet @kevinswiber I did not see a reply in the issue to my idea that we include query among the special-cased fields rather than relegating it to additionalOperations, since it is on the verge of becoming an IANA-registered general-purpose (non-WebDAV) HTTP method. I would prefer that approach.

I don't have a strong preference either way. If it's about to be a "well known" method/verb, I think it makes sense to hoist it. Added it (push soon).

[handrews]

Thanks for catching and fixing my copy-paste error!

[baywet]

@ralfhandl for a final review/approval/merge with the latest minor edits

[ralfhandl]

+1, just one typo and one omission