BHoM_Adapter: UpdateProperty - return consistency with other methods

See also https://github.com/BHoM/BHoM_Adapter/issues/135

#### Broken rules:
The UpdateProperty interface returns the number of objects updated, while the Push returns the list of objects pushed (and therefore potentially updated). I am not sure this logic makes sense other than "We coded what we needed to get what we wanted" kind of way.

It's possible that the UpdateProperty return type has not changed since the Push was returning a boolean, as it has not been in use that much at all.

#### Suggested changes to restore compliance:
Change the return type of the UpdateProperty to return the List of objects with the updated properties.

## Additional note
Note that UpdateProperty is implemented only in 3 Toolkits, so we can postpone this as explained also in my comment below.