Simpler way of modifying JSON documents

To modify a value inside a tree of nested objects, one has to store a copy of each object up until that tree, change the value and re-insert the objects in backward order. Deeper the value to be changed is, more complicated it becomes.

For example, with only 1 level it is already:

QJsonDocument doc = ...;
auto root = doc.object();
auto object1 = root.value("object1").toObject();
object1.insert("value", "some value");
root.insert("object1", object1);
doc.setObject(root);