[DependencyInjection] [ContainerBuilder] Clone abstract Definintions.

This PR makes it possible to easily fetch concrete implementations
of abstract Definintions. It is possible to configure the Definition
instance with a Closure as second argument.

Bug fix?          no
New feature?   yes
BC breaks?     no
Deprecations? no
Tests pass?    yes
Fixed tickets   None
License           MIT
Doc PR           None