💥 revise hook/var fns naming convention (2/2)

This is second of three big naming convention changes. In this commit,
we change the naming conventions for hook functions and variable
functions:

1. Replace the bar | to indicate a hook function with a -h suffix, e.g.

     doom|init-ui -> doom-init-ui-h
     doom|run-local-var-hooks -> doom-run-local-var-hooks-h

2. And add a -fn suffix for functions meant to be set on variables,
   e.g.

     (setq magit-display-buffer-function #'+magit-display-buffer-fn)

See ccf327f8 for the reasoning behind these changes.

modules/term/vterm/autoload.el

@@ -33,7 +33,7 @@ If prefix ARG is non-nil, recreate vterm buffer in the current project's root."
       (setenv "PROOT" (or (doom-project-root) default-directory))
       (let ((buffer (get-buffer-create buffer-name)))
         (with-current-buffer buffer
-          (doom|mark-buffer-as-real)
+          (doom-mark-buffer-as-real-h)
           (vterm-mode))
         (pop-to-buffer buffer)))))