Property Resolution - resolve onto ref objects, not copies of objects they reference.

Part of fix for DFDL-1444 is changing the behavior of property resolving so that it is done in a way that enables sharing, and doesn't require backpointers from elements to the elementRef that refers to them.

This ticket is for the task of fixing property resolution so that element refs, group refs, etc. do not get pointed back to, but rather point at, and gather up property resolutions onto themselves.