[Contracts] Mint hypercert

[bitbeckers]

• [X] Struct for the hypercert data (6 dimensions, see below)
• [x] uri in token points to unstructured data on IPFS (i.e. provide CID)
• [X] input hypercert data in method call
• [X] check on overlap creators-claim

Mappings

mapping(user => [impactHashes])
mapping(impactHash => HyperCert{})

Struct representing the 6 dimensions of impact hyperspace:

        { 
       creators: [ethAddress1, ethAddress2, ...],
        work_scope: "implemented MVP spec",
        work_time: [12312352354,43256345677],
        impact_scope: "all",
        impact_time: [32312352354,63256345677],
        rights: "..." }