Support for replacing JSON field when Kind doesn't match

[JeroenSoeters]

Often I want to update a JSON field with a different type of value. Like:

{
    "property": "value"
}

to

{
    "property": { "nested": "value" }
}

Right now this is not possible as the walker returns an error if the Kind doesn't match. It would be useful if there was an Option to configure this behavior. Instead of throwing an error it would add a replace operation to the patch. We would still default to returning the error of course.

Let me know if this makes sense and I can open a PR for this.