Add support for reciprocal properties - when an entity references another one with memberOf - add hasMember to the target

[ptsefton]

Also make this extensible so that new pairs of properties can be added to the spreadsheet

[ptsefton]

memberOf/hasMember and partOf/hasPart are already implemented in RO-Crate-excel

NOTE: we need to use pcdm:memberOf and pcdm:hasMember cos of changes to schema.org

However, we should make this extensible and move it to RO-Crate-js. Unfortunately we cannot use the context to mark terms as reverese of each other but maybe can do something with adding definitions to the crate with owl:inverseOf and/or provide a function to which you can pass pairs of URIs that should be considered inverses of each other.