Allow manual disabling for One side cross-repository link

[artem-v-shamsutdinov]

By default the relation edges (many-to-many links) will be present in the repository containing the One side of a relationship. There may be cases where the developer intends to allow only one-directional repository navigation (from the Many side).

Provide a way to remove a link to one of repositories (or links to all or many of repositories) on the Many side. This can be done by creating a property on the edge table that will signify if a given relationship should be present in the One side repository or not.

Maintenance of this relationship may be done via a utility function like:

unlinkRepositories(oneSideEntity, oneSideEntity.crossRepositoryOneToMany)
unlinkRepositories(oneSideEntity, oneSideEntity.crossRepositoryOneToMany, oneSideEntity.crossRepositoryOneToMany[2])
unlinkRepositories(oneSideEntity, oneSideEntity.crossRepositoryOneToMany, oneSideEntity.crossRepositoryOneToMany.slice(2, 4))

an inverse function can also be provided:

linkRepositories(oneSideEntity, oneSideEntity.crossRepositoryOneToMany)
linkRepositories(oneSideEntity, oneSideEntity.crossRepositoryOneToMany, oneSideEntity.crossRepositoryOneToMany[2])
linkRepositories(oneSideEntity, oneSideEntity.crossRepositoryOneToMany, oneSideEntity.crossRepositoryOneToMany.slice(2, 4))

This will flip a flag on the edge record for each of the OneToMany child records specified. The in memory value of this can be kept in entityState property (which may have to be expanded from being a plain enum to a record)