Rename AnnotationDescriptorLoader, ConstantDescriptorLoader and DescriptorLoadersStorage before conversion
Convert AnnotationDescriptorLoader, ConstantDescriptorLoader and DescriptorLoadersStorage
Prettify AnnotationDescriptorLoader, ConstantDescriptorLoader and DescriptorLoadersStorage after conversion
Merge AnnotationLoader and ConstantLoader into single interface

Merge all implementation classes into single BinaryClassAnnotationAndConstantLoader
Extract non-descriptor specific abstract ancestor for BinaryClassAnnotationAndConstantLoader
Fix calling toString() on ProtoContainer