Set custom locale key string for prototypes

[Afforess]

It is fairly common for mods to copy/re-use existing prototypes (from vanilla or another modded type) and copy it, but there is no way to retain the old locale text for the new copied entities. The locale string seems to be auto-generated based on the prototype type and prototype name, so copies must have their own locale text.

This is not ideal because while it is easy for modders to simply copy/paste the English string into their locale.cfg file in their mod, no one takes the time to copy all the foreign translations with it. So "copies" of prototypes stay translated in English, but lose all the foreign translations existing prototypes have.

What could solve this would be an optional field in a prototype, to set the locale key to another name, so you could re-use existing locale text.