[GR-60080] Add reference map support for runtime allocated DynamicHubs.

[graalvmbot]

• Replaced DynamicHub.referenceMapIndex with a heap-base relative offset that directly points to the hub's InstanceReferenceMap(see DynamicHub.compressedReferenceMapOffset). The compressedReferenceMapOffset is computed at build-time in NativeImageHeap.countPatchAndVerifyDynamicHubs().
• Added the class RuntimeInstanceReferenceMapSupport, which manages InstanceReferenceMaps for DynamicHubs that are loaded at run-time.
• Removed some @AutomaticallyRegisteredImageSingleton annotations. Affected singletons are now registered in feature classes, to make it clearer to which feature a singleton belongs to.
• Renamed LayeredImageHeapObjectAdder to ImageHeapObjectAdder. This singleton is now registered unconditionally.
• Various cleanups.