Improve ivy-switch-buffer transformer

- Highlights remote/tramp files with ivy-remote face
- Highlights non-file-visiting buffers with ivy-subdir face
- Highlight modified buffers with ivy-modified-buffer face
- Disable built-in ivy-switch-buffer transformer (redundant with our own
  transformer)

modules/completion/ivy/config.el

@@ -106,6 +106,10 @@ immediately runs it on the current candidate (ending the ivy session)."
                          ((all-the-icons-icon-for-file (:width 2 :align right))
                           (ivy-rich-candidate)))))))
 
+  ;; Remove built-in coloring of buffer list; we do our own
+  (setq ivy-switch-buffer-faces-alist nil)
+  (ivy-set-display-transformer 'internal-complete-buffer nil)
+
   ;; Highlight buffers differently based on whether they're in the same project
   ;; as the current project or not.
   (let* ((plist (plist-get ivy-rich-display-transformers-list 'ivy-switch-buffer))