Returns a list of all component classes.
Usage
List all component classes:
mix dog.safelist -m MyAppWeb.CoreComponentsWrite classes to file:
mix dog.safelist -m MyAppWeb.CoreComponents -o assets/doggo_safelist.txtCheck whether a file is up-to-date:
mix dog.safelist -m MyAppWeb.CoreComponents -o assets/doggo_safelist.txt --check