Custom Machinery 1.21.1-0.10.9

Additions :

• A default background will be added to the machine gui when the first element is added through the editor.
• Add 'working_core' requirement to make recipe start only if another core is processing a recipe.
  • More info on its wiki page : Json - KubeJS

BugFix :

• Fix energy not showing correctly in jei.
• Fix transfer item button appear in jei even if the recipe doesn't need items.
• Fix ghost item transparency not working.