add sdg and sdgTarget to classificationScheme codelist

[odscjen]

closes #1098

Copied from OC4IDS codelist and used https://unstats.un.org/sdgs/indicators/indicators-list/ as the source rather than https://sdgs.un.org/goals

[jpmckinney]

The Category is purpose but OCDS doesn't have a purpose field like OC4IDS.

I think it's meant to be item? The other options so far in this codelist are legalBasis and organization.

[odscjen]

Good catch, but I think it should be 'tender' as its the tender that's being classified not any particular items within it. Tender is used as the category in the Tender classification extension

[jpmckinney]

We haven't used 'tender' yet (except in that extension), and many of the 'item' classifications can be used in both 'tender' and 'item' context.

For example, the EU profile uses tender.classification with CPV codes, because the EU doesn't subdivide procedures or lots into individual items.

So, I would use 'item', since presumably individual items can be tagged as SDG-related.

[jpmckinney]

On second thought, if we only expect a procedure to be tagged with SDGs, then we can leave it as 'tender'.