lang/org: refactor org config load order

- No longer use org-load-hook; it was unnecessary and there were corner
  cases where org would get loaded before hooks were added to it.
- Update comments
- Remove config that was redundant with org's defaults (wrt org-file-apps)
- Perform persp-mode check before using persp-mode API in
  +org|exclude-agenda-buffers-from-workspace advice.
- Update outdated smartparens config and move it out of
  org-mode-hook (only needs to be run once, not everytime org-mode is
  enabled)
- Autoload mode hooks

modules/lang/org/+babel.el

@@ -28,6 +28,9 @@ at the first function to return non-nil.")
       org-src-window-setup 'current-window
       org-confirm-babel-evaluate nil) ; you don't need my permission
 
+;; Use major-mode native TAB indentation in SRC blocks
+(advice-add #'org-return-indent :after #'+org*fix-newline-and-indent-in-src-blocks)
+
 (defun +org*babel-lazy-load-library (info)
   "Load babel libraries lazily when babel blocks are executed."
   (let* ((lang (nth 0 info))