def-advice!->defadvice! & conform to new advice conventions

This commit does two things:

- Renames def-advice! to defadvice!, in the spirit of naming convenience
  macros after the function/macro they enhance or replace.
- Correct the names of advice functions to indicate visibility and
  intent. A public advice function like doom-set-jump-a is meant to be
  used elsewhere. A private one like +dired--cleanup-header-line-a
  shouldn't -- it likely won't work anywhere but the function(s) it was
  made to advise.

modules/ui/neotree/config.el

@@ -49,7 +49,7 @@
     (defun +neotree-fix-cursor-h (&rest _)
       (with-current-buffer neo-global--buffer
         (+neotree*indent-cursor))))
-  (def-advice! +neotree-indent-cursor-a (&rest _)
+  (defadvice! +neotree--indent-cursor-a (&rest _)
     :after '(neotree-next-line neotree-previous-line)
     (beginning-of-line)
     (skip-chars-forward " \t\r")))