Add parts method to PaperSkinPartBuilder

Introduce the `parts` method, allowing direct handling of `SkinParts` objects by converting them to raw values. This improves usability and aligns with the existing builder pattern.

src/main/java/net/thenextlvl/character/plugin/character/PaperSkinPartBuilder.java

@@ -74,6 +74,11 @@ public SkinPartBuilder show(SkinLayer layer) {
         return raw(raw |= layer.getMask());
     }
 
+    @Override
+    public SkinPartBuilder parts(SkinParts parts) {
+        return raw(parts.getRaw());
+    }
+
     @Override
     public SkinPartBuilder raw(int raw) {
         this.raw = raw;