Refactor DataObjectCodecContext augmentation handling

ClassLoadingStrategy is now integrated into BindingRuntimeContext, which means we can load all augmentations that are reachable for a particular SchemaContext.

This is a key simplification, as now we do not have to worry about the set of possible classes expanding based on the invocation context (such as would be possible with Thread context class loading strategy).

The benefit is that we can simplify augmentations fields in DataObjectCodecContext and make them pure caches. Most notably we should have enough knowledge so that we run reloadAllAugmentations() exactly once and also should not fiddle with a Class's ClassLoader in augmentationByClass().