Save recipe edits as a variant linked to the original

> Suggestion on edit mode: Allow the user to save the edits as a variant of the recipe. I often take a recipe I'm given, cook it, then as I see things I'd want to change (e.g. more garlic, cut out the lemon juice, etc.) I'd want make those edits, but if I saved them as a new recipe, I could always retain the original if someone wanted to see what it came from or if I wanted to give that one a try. It kinda shows the lineage of the recipe, especially if a back link gets added to the new recipe.

_Originally posted by @omeganot in [#205](https://github.com/cooklang/cookcli/issues/205#issuecomment-3623558109)_