Revert "Revert "Adapt to generalization of ::getSubResourcesAssayMultiMap""

This reverts commit f3f76cf45cec600ef5aa3a7564710dd74f9a3f01.
Revert "Revert "Fix test" - this seems to break all production builds"

This reverts commit f29cb23cae125870b6cf5f7461da7686f3e7b9a7.
Move HighDimensionResourceService out of grails-app/services

See comment in commit.