Customizable Player Models

Added copy color option to copy transforms
Added additive option to copy transforms
Added multiply option to copy transforms
Updated Simplified Chinese translations (#803)

Fixed animation editor not working on 1.21.7 (Closes #798)
Fixed crash with Minecraft Forge 1.21.7 (Closes #799)
Fixed crash with Iris or Vivecraft on 1.21.7 fabric (Closes #800)
Fixed load from skin not working with server-side skin changers or via-version proxies (? #659)
Fixed hunger, health and air animations not working on dedicated servers for other players (Closes #804)
Fixed crash with real camera (Closes #807)