optional ClassFilter spi

in several cases it's needed to get rid of beans and/or pre-defined beans.
that's possible with @Exclude, @Vetoed, @Typed(), scan-tag and ProcessAnnotatedType#veto.
only #veto supports really dynamic cases - esp. in cases you don't have the class/es in question under your control (or diff. teams have diff. requirements).

a simple (but optional) ClassFilter spi allows:

• full control (like with #veto - just simpler)
• the concept of overruling based on config-ordinals
• to get rid of special behaviors defined for alternative-beans (see e.g. observers in alternative-beans)
• to use the concept itself for different features/use-cases
  (e.g. a class-filter per test-class via @TestControl to support more isolated tests)