Add byPropertyListSerialization Options and use

This introduces options to make grouping by property
in serialization optional for claims, qualifiers and
references as well as using them!

The default is that all of the three above are
grouped by property

REQUIRES I523536b8bf6e0 in WikibaseDataModel

Change-Id: I3fdb0b6ed2dfee751316662f9cd91fe9c4421c45
Merge "Add byPropertyListSerialization Options and use"