Columns not in the model cause Patch based on NewtonsoftJson to crash

[mykola384]

When you send a json to patch, when the json has fields missing from the model, when it is a class, the exception "System.InvalidOperationException : Sequence contains no matching element" is thrown.

To reproduce it, go to the unit test Morcatko.AspNetCore.JsonMergePatch.Tests.NewtonsoftJson.Patching.Attributes.CannotPatchSubObject and change

"{'obj_property': { 'id': 3 }}");

to

"{'obj_other_property': { 'id': 3 }}");

I tracked it down to Morcatko.AspNetCore.JsonMergePatch.Internal.ReflectionHelper.GetJsonProperty which calls Single on properties list and the list is missing the specified property.

I think it would be useful to be able to patch a json with a document that has a random json inside - as when you have a document DB as a storage, you don't always need to have a strongly typed structure to store it.

Maybe, there are alternatives in how to do it?

[Morcatko]

I guess it makes sense to ignore it in some cases. I think it should be optional - fail by default, but option to ignore it.

Feel free to create a PR.