Gracefully handle properties with no setters

[Blackclaws]

My datatypes sometimes have properties that calculate based on other properties for convenience.

While this is no problem on the serialization side of things. Reading such a compound type throws an exception because no setter can be found for the property.

My expectation would be that the missing setter is gracefully ignored.

[Blackclaws]

Potentially related to https://github.com/Apollo3zehn/PureHDF/issues/117