Allow override of model element registration in DI

[gfontorbe]

Allow the element registration from the dependency injection to be overridden by another ContainerModule. This comes in handy when working with exported containers from the sprotty-library or when sharing a ContainerModule when only a subset of model elements need a new registration.

This introduces a new helper function overrideModelElement to be used instead of configureModelElement in the ContainerModule

Example:

const moduleA = new ContainerModule((bind, unbind, isBound, rebind) => {
...
configureModelElement(context, 'myElementType', MyElementImplA, MyElementViewA);
}

const moduleB = new ContainerModule((bind, unbind, isBound, rebind) => {
...
overrideModelElement(context, 'myElementType', MyElementImplB, MyElementViewB);
}

const container = new Container();
loadDefaultModules(container);
container.load(moduleA);
container.load(moduleB);

In this scenario, myElementType elements will first be linked to MyElementImplA and MyElementViewA before being linked to MyElementImplB and MyElementViewB.

If the order of the functions container.load(...) are reversed, so is the link between the element type and its implementation/view.

Error handling:
By design, we can only override an element that has already been configured.

• Trying to use configureModelElement on an element type that is already registered will throw an error
• Trying to use overrideModelElement on an element type that is not already registered will throw an error

[sailingKieler]

I like it! 👍

[spoenemann]

Great enhancement!