Enable filling get only ICollection property

[ADIX7]

A get-only property can not be set but if it is an ICollection and the constructor initialized it we can copy the deserialized items with Add.

This yaml currently can't be deserialized to the class below.

contents:
- asd1
- asd2
- asd3
- asd4

public class Container
{
    public List<string> Contents { get; } = new List<string>();
}

[aaubry]

I've reviews these changes and they seem fine. Could you add some tests to show that the feature works as intended? Thanks

[aaubry]

Any news, @ADIX7 ?

[ADIX7]

Sorry, I didn't had any time finish this.

[EdwardCooke]

This PR appears to be abandoned, it's over a year old. I'm going to close it.