lang/org: general refactor; split init into hooks

lang/org's initialization process is now split up into hooks on
org-load-hook. This approach is cleaner and easier to customize. I also
removed the escape binding in org-agenda-mode-map, as the popup system
makes it redundant.

modules/lang/org/+babel.el

@@ -1,5 +1,7 @@
 ;;; lang/org/+babel.el -*- lexical-binding: t; -*-
 
+(add-hook 'org-load-hook #'+org|init-babel)
+
 (defvar +org-babel-languages
   '(calc
     css
@@ -23,7 +25,7 @@
   "A list of org-babel languages to load.")
 
 
-(after! org
+(defun +org|init-babel ()
   (setq org-src-fontify-natively t      ; make code pretty
         org-src-preserve-indentation t  ; use native major-mode indentation
         org-src-tab-acts-natively t