CASC creation from scratch

[barncastle]

It should probably be implemented for those daring enough to try.

@justMaku has started this: https://github.com/justMaku/CASCHost/tree/casc_builder

• Handler constructors exist however I can't remember the state of these.
• Order of operations may need changing.
• Configs are generated from existing Blizzard ones so will need rewriting(?).
• Potentially implement encryption (is it worth it?).

Probably a load of other things too...

[bloerwald]

https://github.com/wowdev/CommunityAddressableStorageContainer Also exists for inspiration, but probably has less than this repo on all fronts.