SpringBoot Add origin support for empty YAML list and map

Add the fix for CollectionNode Add some test

Comment From: yan-khonski-it

When do you merge it? In which Spring Cloud Config version is this fix coming?

Comment From: wilkinsona

@yan-khonski-it This pull request is still open and has not yet been merged.

Comment From: philwebb

Thanks very much for the contribution @unix1982. This is in master and will be part of 2.4.