Produce complete ONIX 3.1

[ja573]

Following #441 we should implemente ONIX 3.1. There are minimal changes to 3.0, but the inclusion of <AffiliationIdentifier> is very interesting

[ja573]

Also the addition of postal addresses for compliance with the EU's General Product Safety Regulation

[ja573]

• Create new specification thoth::onix3.1, copying the content of the file from existing ONIX 3.0 (data.rs)
• Review what's new in ONIX 3.1
• Implement anything that we can already support
• Note anything that requires extra fields/tables
• Start implementing new data fields (use new minor version for migration v0.14.0)

[tosteiner]

Looks like there are more incoming requirements that might be good to implement, see "European Directives, ONIX, and the Importance of Metadata in the International Book Supply Chain" video from BISG https://knowledgecenter.bisg.org/23c9o46/

Requirements relate to:

• European Accessibility Act (EAA)
• EU Regulation on Deforestation-free Products (EUDR) (for print titles),
• General Product Safety Regulation (GPSR).

And do we also need to include these in the "older" ONIX 3.0 specifications? EditEUR notes that the EU regulations will be compatible with ONIX 3.x, so can also be included in 3.0.x records.