Add IPP attributes and enums

[StefanScherer]

For an IPP project that also uses the IPP Shared Infrastructure Extensions (sample ippserver at https://istopwg.github.io/ippsample/) I need some missing attributes and enums.

[williamkapke]

Nice! Which spec(s) reference the additions in enums.js?

[StefanScherer]

I've added a comment in our fork at https://github.com/sealsystems/node-ipp/blob/sealsystems/lib/enums.js#L165 -> http://ftp.pwg.org/pub/pwg/candidates/cs-ippinfra10-20150619-5100.18.pdf

We did a PoC with IPP Shared Infrastructure Extension (INFRA).

[gmuth]

@williamkapke, the enum values are documented in section 6 of the iana ipp registrations. In order to display value names and not numbers I chose another approach (in my kotlin implementation): parse the official csv files at startup and later lookup the values stored in maps.

getEnumValueName("job-state", 3) -> pending

https://github.com/gmuth/ipp-client-kotlin/blob/master/src/main/kotlin/de/gmuth/ipp/iana/IppRegistrationsSection6.kt