Database requirement: triple store / graph database solution

This issue documents the requirement for a triple store (or well-structured relational database workaround) to store assets and their relationships collected in e.g. CCT1 "Kartierung" & survey efforts.

also see (Recommendations concerning semantics with regard to mapping and survey, 2020-12-03): https://nubes.helmholtz-berlin.de/apps/onlyoffice/470737845?filePath=%2FHMC_Core%2F05_HMC-CCTs%2FCCT1%20Mapping%2FTF2%20Categories%2F2020-12-03_Recommendations_Semantics_and_Interoperability.docx

b) Expression as graph or network object Technically, such a map is typically expressed as a graph or network object, where nodes correspond to assets and edges their relationships. Each node and edge can have metadata associated with it, and the topology of the overall graph can provide insight into hubs, bridges, cliques, and other features which can guide HMC strategy and action.

c) Graph construction from diverse formats possible and storage in graph database In terms of storage, a graph object can be constructed from multiple formats, including well-structured tables and RDF-type triples. The graph can also be stored in graph database solutions, such as Neo4j or GraphDB. This has an advantage of being compatible with semantic graphs.