Adapt Funding Request and Invoice JSON import mechanisms to support new identifiers

[SvenMarcus]

The JSON imports are from a time when we had to use mainly name based matching.
We can now use identifiers/links to better refer to related entities.

Institutions:

• ROR
• Crossref ID
• CODA internal ID

Funding Organizations:

• ROR
• Crossref ID
• DOI

Contracts:

• ESAC
• openCost ID?
• ???

Creditors:

• ???

Budgets:

• keep using name?

Institution backed funding source:

• ROR
• Crossref ID
• CODA internal ID