Fix PBR specular & normal textures getting ignored

[RecursivePineapple]

• Stack was being overfilled by MemoryStack
• Added tons of logging for ignored important exceptions
• Added missing interface on mixin (should it be moved to gtnhlib?)
• Move PBR debug to angelica config (was a system property)

[RecursivePineapple]

I swapped the MemoryStack to a heap alloc because I kept getting stack overflow errors from the stack alloc. The exceptions were ignored due to all of the empty catches, so I added some logging there to prevent this from happening again.
The method I changed is only used to download GPU textures onto the CPU so that the PBR atlas can be dumped to a file. It's only ran when PBR dumping is enabled, and even then it's only ran once.

There was a ClassCastException being ignored too, so I added the interface to the accessor mixin which was missing it.