Allow to append to multi-valued properties using Document.Update operation

When updating multi-valued properties using the Document.Update operation, the value is always replaced by the new value. If we want to append a new value to the list, we need to know the value before, append the new value and use that as a new value.
This can't work while using bulk edit feature.

We want to be able to define a behavior per multi-valued properties when using Document.Update:

• replace: replace the old value by the new value, existing behavior.
• append_excluding_duplicates: append the new value to the existing list value, ignoring any new value duplicates.
• append_including_duplicates: append the new value to the existing list value, including all duplicates.

To do that, add a new parameter propertiesBehaviors to the Document.Update operation, same type as the properties one to define the behavior of the properties, if any.

dc:subjetcs=append_excluding_duplicates
dc:subjetcs=append_including_duplicates
dc:coverage=replace

No behavior defined means replace.

When using the append_excluding_duplicates option:

• Values that do not exist already in the destination documents are added
• Already existing values are ignored. e.g. If dc:subjects already contains art/architecture and the user adds it using the bulk edit form, it is only stored once in the document. It triggers a server side log for debugging purpose but does not trigger an error preventing the action from going through.

When using the append_including_duplicates option:

• All values are added regardless of whether they are already present in the destination documents or not