Added support for empty field arrays in mappings

Fix for #6133, added the ability to send empty arrays as part of an index mapping json. For single and multi field properties objects

Sorry for the import changes, IntelliJ doesn't like eclipse imports and fights it like the devil.

If the test are in a non standard format please advise. I just find them easier to read like this.


I have a similar concern here for when entry.getValue is not a Map