Add FundingReference class

[RKrahl]

This is similar in nature as #248. I put put it up for discussion, although I'm not certain myself, which variant I would prefer.

In #200, I proposed schema extensions to support data publication workflows. This proposal was addressing a particular use case of making curated data publications. It included a new entity FundingReference. But this was formulated in a way that it could only be used in relation with a DataPublication. Now there may be other use cases where funding information may be needed. This could be relevant when simply minting DOIs for investigations rather then making curated data publications. But it may also be useful in general to collect this information already in the user office, when submitting the proposal and store it with the investigation.

So this would amend #200 in storing the FundingReference independently of DataPublication. It would consist of the following classes:

FundingReference

Information about financial support

Constraint: funderName, awardNumber

Relationships:

Card	Class	Field
0,*	InvestigationFunding	investigations
0,*	DataPublicationFunding	publications

Other fields:

Field	Type
funderName	String[255] NOT NULL
funderIdentifier	String[255]
awardNumber	String[255] NOT NULL
awardTitle	String[255]

InvestigationFunding

Relation between an investigation and a funding reference

Constraint: investigation, funding

Relationships:

Card	Class	Field
1,1	Investigation	investigation
1,1	FundingReference	funding

DataPublicationFunding

Relation between an data publication and a funding reference

Constraint: dataPublication, funding

Relationships:

Card	Class	Field
1,1	DataPublication	dataPublication
1,1	FundingReference	funding