feat(workspaces): +workspace/switch-to: add buffer list column

To offer more context for ivy users while switching between workspaces.

Close: #3006
Co-authored-by: rgrinberg <rgrinberg@users.noreply.github.com>~

modules/ui/workspaces/autoload/ivy.el

@@ -0,0 +1,17 @@
+;;; ui/workspaces/autoload/ivy.el -*- lexical-binding: t; -*-
+;;;###if (modulep! :completion ivy)
+
+;;;###autoload
+(defun +workspace--ivy-rich-preview (workspace)
+  (if-let (buffers (when-let (workspace (gethash workspace *persp-hash*))
+                     (cl-loop for (type . rest) in (persp-window-conf workspace)
+                              if (eq type 'buffer)
+                              collect (car leaf)
+                              else if (eq type 'leaf)
+                              append (cl-loop for (type . leaf) in rest
+                                              if (eq type 'buffer)
+                                              collect (car leaf)))))
+      (string-join buffers " ")
+    "*No buffers*"))
+
+;;; ivy.el ends here