Ensure the `if-let*` macro definitions is available during compile-time
Adds `org-roam-buffer-no-delete-other-windows`, which controls the behaviour of the org-roam buffer side window upon `delete-other-windows`.
Split functionality related to the org-roam-buffer into its own feature/file. Introduce `org-roam-buffer-prepare-hook' to allow customizations of the org-roam-buffer content. Co-authored-by: Jethro Kuan <jethrokuan95@gmail.com>
