Refactor Project API to reflect changes upstream

projectile-project-root no longer returns `default-directory` if not in
a project (it returns nil). As such, doom-project-* functions (and their
uses) have been refactored.

+ doom-project-p & doom-project-root are aliases for
  projectile-project-p & projectile-project-root.
+ doom-project-{p,root,name,expand} now has a DIR argument (for
  consistency, since projectile-project-name and
  projectile-project-expand do not).
+ The nocache parameter is no longer necessary, as projectile's caching
  behavior is now more sane.
+ Removed some projectile advice/hacks that are no longer necessary.
+ Updated unit tests

modules/ui/treemacs/autoload.el

@@ -10,8 +10,8 @@
       (treemacs-do-remove-project-from-workspace project))
     (with-current-buffer origin-buffer
       (treemacs-do-add-project-to-workspace
-       (treemacs--canonical-path (doom-project-root 'nocache))
-       (doom-project-name 'nocache))
+       (treemacs--canonical-path (doom-project-root))
+       (doom-project-name))
       (setq treemacs--ready-to-follow t)
       (when (or treemacs-follow-after-init treemacs-follow-mode)
         (treemacs--follow)))))