Refactor DOOM init & add new init hooks

+ Add doom-init-hook and doom-post-init-hook to simplify Emacs init
  hooks into less ambiguous ones.
+ Attach former after-init-hook and emacs-startup-hook hooks to new doom
  init hooks.
+ Vastly improves daemon and tty support: preventing incorrect colors
  from bleeding across face class barriers, and into GUI Emacs and vice
  versa, when spawned with emacsclient.
+ Fix persp-mode breaking Emacs daemon, and ensuring that initialization
  is done properly in terminal Emacs (and emacsclient frames).

modules/completion/helm/config.el

@@ -33,7 +33,7 @@
 
   :config
   (load "helm-autoloads" nil t)
-  (add-hook 'emacs-startup-hook #'helm-mode)
+  (add-hook 'doom-init-hook #'helm-mode)
 
   (defvar helm-projectile-find-file-map (make-sparse-keymap))
   (require 'helm-projectile)

modules/completion/ivy/config.el

@@ -40,7 +40,7 @@ session)."
   (after! magit     (setq magit-completing-read-function #'ivy-completing-read))
   (after! yasnippet (push #'+ivy-yas-prompt yas-prompt-functions))
 
-  (add-hook 'emacs-startup-hook #'ivy-mode)
+  (add-hook 'doom-init-hook #'ivy-mode)
 
   (map! :map ivy-mode-map
         [remap apropos]                   #'counsel-apropos