emacs: Rename internal procedures.

* emacs/guix-list.el (guix-list-get-param-title): Rename to...
  (guix-list-param-title): ... this.
  (guix-list-get-column-format): Rename to...
  (guix-list-format): ... this.
  (guix-list-get-displayed-params): Rename to...
  (guix-list-displayed-params): ... this.
  (guix-list-get-sort-key): Rename to...
  (guix-list-tabulated-sort-key): ... this.
  (guix-list-make-tabulated-vector): Rename to...
  (guix-list-tabulated-vector): ... this.
  (guix-list-get-list-format): Rename to...
  (guix-list-tabulated-format): ... this.
  (guix-list-get-tabulated-entries): Rename to...
  (guix-list-tabulated-entries): ... this.
  (guix-list-get-tabulated-entry): Rename to...
  (guix-list-tabulated-entry): ... this.
* emacs/guix-info.el (guix-info-get-displayed-params): Rename to...
  (guix-info-displayed-params): ... this.
* emacs/guix-base.el (guix-get-params-for-receiving): Adjust
  accordingly.
  (guix-get-name-spec): Rename to...
  (guix-package-name-specification): ... this.
  (guix-get-full-name): Merge this and...
  (guix-entry-to-specification): ... this into...
  (guix-package-entry->name-specification): ... this.
  (guix-get-installed-outputs): Rename to...
  (guix-package-installed-outputs): ... this.
  (guix-get-package-id-and-output-by-output-id): Rename to...
  (guix-package-id-and-output-by-output-id): ... this.