folder-based hair and ACS sprites

[ThePotatoGuy]

#8596

Key Changes

• hair and ACS sprite objects now support folder-based organization, basically similar to clothes:
  • h/<hair name>/front.png or h/<hair name>/0.png
  • a/<acs name>/0.png
• sprite JSONs support the new format as well
• a simple bash script for renaming using git is provided, but a full-fledged spritepack updater will be added in spack updates part 2 #9729

Testing

• verify that all current sprites load correctly
• verify spritepacks with jsons do not break - testing of the new json props should be in spack updates part 2 #9729 for ease of testing