If `OnBeanCondition` is used with a `String` literal representing the
fully qualified name of a bean and such type does not exist, it
gracefully manages it as if it was not found. Prior to this commit, an
exception would be thrown if any related class such as the parent
class does not exist.

This commit handles this additional case, catching `NoClassDefFoundError`
the same way it did handle `ClassNotFoundException`. That way, a
missing type will now be considered as absent if it's not on the
classpath.

Closes gh-7459