Rework `list-recipes` based on suggestions from @timsutton.
-- use autopkglib's `get_identifer_from_recipe_file` no need to duplicate
-- default list will only show a recipe's override not it's parent recipe
-- it is possible to get both override and it's parent if the `--show-all` optarg is used
-- if the `--plist` optarg is set it will return all keys/values.  (no more -x optarg)
-- safer determination of environment HOME value
-- switched out single quote for double