Short version:
Add support for localised_name in item creation. Note that it is already supported for recipe creation.
Maybe also for entity creation.
Also localised_name for LuaRecipe so that it can be accessed in control.lua.
Long version:
During the development of Creative Mode, I saw the localised_name property in http://lua-api.factorio.com/0.13.5/LuaI ... otype.html. I gave it a try when creating the free fluid recipes in data-final-fixes.lua and it is working. It gave me the ability to support all fluids from other mods without the need of localising them myself.
However, during the discussion with Choumiko here, we realised that it is not supported for item creation. The property is simply ignored and unknown keys are still being displayed.
I haven't tried entity creation with localised_name yet, maybe we will need it too.
In addition, I found that localised_name is not on http://lua-api.factorio.com/0.13.5/LuaRecipe.html, maybe someone will need it? I think we should keep these to be consistent anyway.
Would love to have it for entities