Asset tree support light/dark variants

[tadhgboyle]

Currently only TinyMCE requires a specific dep (prism) in a specific colour scheme (light/dark), so this is hard coded. However, it would be nice to have a better solution for this. Samertons original comment: https://github.com/NamelessMC/Nameless/pull/2670#discussion_r863103559

We cannot check constants within the asset tree array, otherwise this would be a perfect solution