[FeatureRequest] Variants of \listremove #33

Not really an urgent issue but for completeness, it would be neat to provide commands which remove expanded items

• \listeremove
• \listxremove
• \listcseremove
• \listcsxremove
  similar to the corresponding add commands
• \listeadd
• \listxadd
• \listcseadd
• \listcsxadd

Originally posted by @mrpiggi in #10 (comment)