More customization options for mannequins

The main idea behind this post is to make it possible to further customize the mannequins that were recently added to Minecraft, specifically in version 1.21.9. Whether these changes are implemented in later versions or not, the goal is to allow the mannequins to not only mimic the movements of a player but also have their bodies separated into parts, like an armor rack. This would facilitate the creation and customization of items within the game, even in the vanilla version.