model.Component: createBindingByFormatter(), getDataScope()

in case we access nested data inside a parent model, it can happen that a key root does not exist inside the current model.

example: data.user.firstname

would try to check if firstname exists on data.user which does not exist here.

so we need to add a check for the scope.

i will also add an empty object into getDataScope() as a placeholder. You can create models without any data which need parent access.