Resolve "(core): add blocker support for IContainer<T>::scoped_emit"
Description
A block() function can now be called in a scoped_emit to prevent the given slot to be called:
const auto scoped_emitter = container->scoped_emit();
scoped_emitter->block(this->slot(IService::slots::UPDATE));
container->push_back(object1);
container->erase(object2);
container->push_back(object3);
Closes #1122 (closed)
How to test it?
This is covered by unit-tests, see ContainerNotifierTest.cpp