Fix problem with top level choice elements not being saved correctly.

- create common function to process a list of properties and to handle choice correctly
- also fixed issued with leaf-list elements and array handling
- rift-16326

Change-Id: I67f10318c47d2efcdc5dc1a81d48bf0d6841a221
Signed-off-by: Bob Gallagher <bob.gallagher@riftio.com>