Expose the current context / scope as a property from the Utf8JsonReader. #1557

namespace System.Text.Json
{
    public ref partial struct Utf8JsonReader
    {
        public JsonContext Context { get; }
        // OR one (or both) of these
        public bool InObject { get; }
        public bool InArray { get; }
    }

    // OR Scope?
    // Can't call it state, since we already have such a concept and overloading it would be confusing
    public enum JsonContext : byte
    {
        Object,
        Array,
        None,
        Value, // Remove? OR split into specific JSON primitives, like String, Number, etc.?
    }
}