Review the new codes from extensions

[jpmckinney]

EU

Codes were last added in https://github.com/open-contracting/standard/pull/1225

See extension changelog https://extensions.open-contracting.org/en/extensions/eu/1.1/#changelog

• documentType
• itemClassificationScheme
• partyRole
• relatedProcessScheme

For now, when merging the 1.1 branch of the extension into its 1.2 branch, I omitted these codelist additions and corresponding readme changes.

New extensions

Non-exhaustive

• https://extensions.open-contracting.org/en/extensions/document_publisher/master/codelists/