refactor(cli): remove :stub, :obsolete, :deprecated, :since

I've removed these CLI properties because they were either
unused (:deprecated and :since) or poorly implemented (:stub and
:obsolete). And I'd rather have fewer magical properties, and instead
delegate these roles to the defobsolete! and (new) defstub!  macros.
Also, in the future, the help API will ascertain :since dynamically, so
it won't be very useful.

In summary:
- Use defstub! instead of :stub
- Use defobsolete! instead of :obsolete or :deprecated
- This removes the doom-cli-deprecated-error type (it's not really an
  error to begin with).
- Removes :stub, :obsolete, :deprecated, and :since

bin/doom

@@ -270,8 +270,8 @@ SEE ALSO:
       ;; (load! "nuke" dir)
       ;; (load! "package" dir)
       ;; (load! "profile" dir)
-      ;; (defobsolete! ((compile c)) "doom sync --compile" "v3.0.0")
-      ;; (defobsolete! ((build b))   "doom sync --rebuild" "v3.0.0")
+      ;; (defobsolete! ((compile c)) (sync "--compile") "v3.0.0")
+      ;; (defobsolete! ((build b))   (sync "--rebuild") "v3.0.0")
       )
 
     (defgroup! "Diagnostics"