#cobblestone_recipes tag

Add a new tag #cobblestone_recipes to Cobblestone, Blackstone, and Cobbled Deepslate.
For every recipe that has minecraft:cobblestone in it, replace the minecraft:cobblestone with, say, minecraft:flag.cobblestone_recipes, and have it set up such that any recipe containing this flag could involve either Cobblestone, Blackstone, or Cobbled Deepslate. It will make implementing new cobblestone variants easier, and similar things could be done for new wood variants or whatever.