* emacs/guix-base.el (guix-package-location): New function.
(guix-edit-package): Rename and move to ...
* emacs/guix.el (guix-edit): ...here. Make it interactive.
* emacs/guix-command.el (guix-edit-action): New function (alias to
'guix-edit') to override the popup for edit command in "M-x guix".
* emacs/guix-list.el (guix-list-edit-package): Adjust for 'guix-edit'
renaming.
* emacs/guix-main.scm (package-location-string): Allow to accept package
id or package name as argument.
