Please add default constructor and move constructor/assignment op to Scope class

Is your feature request related to a problem?
I have event loop which gets objects from a queue and processes them. I want to create Span in this loop and set is as active span. Some of these objects are for health checks, and I want to exclude them from telemetry. Span objects are stored in nostd::shared_ptr, so I can declare variable first and then conditionally assign value to it. However I cannot do the same with Scope object, declaration and initialization must happen at the same time.

Describe the solution you'd like
Please add default constructor and move constructor/assignment operator to Scope class. This would allow to create empty Scope object first, and then conditionally move-assign value later.

Describe alternatives you've considered
Now I need to create two code branches - one for tracing enabled where code creates Scope object and perform processing, and another with processing only.

Additional context
This sample code presents what I would like to do:

void EventLoop()
{
    while (1)
    {
        auto obj = queue->Dequeue();
        
        opentelemetry::nostd::shared_ptr<opentelemetry::trace::Span> span;
        opentelemetry::trace::Scope scope;
        if (obj->TraceEnabled())
        {
            span = tracer->StartSpan(obj->GetName());
            scope = tracer->WithActiveSpan(span);
        }
        
        obj->Run();
        
        if (nullptr != span)
            span->End();
    }
}