All the other annotation classes has abstract modifier.
All nested interfaces has static modifiers.
This commit is not so important for compiler, but it is matter for IDE,
because when we load classes in IDE via
KtLightClassForDecompiledDeclaration -- there are Abstract and Static
on the Container class
Allow to get annotation list and to invoke `findAnnotation` without building delegate
Introduce KtLightNullabilityAnnotation which holds nullability information and is built
before delegate is built
Stanislav Erokhin