refactor: move Notebook enums to their own file (#6220)

Co-authored-by: Mm2PL <miau@mail.kotmisia.pl>

src/widgets/Notebook.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "widgets/BaseWidget.hpp"
+#include "widgets/NotebookEnums.hpp"
 
 #include <pajlada/signals/signal.hpp>
 #include <pajlada/signals/signalholder.hpp>
@@ -21,17 +22,6 @@ class NotebookTab;
 class SplitContainer;
 class Split;
 
-enum NotebookTabLocation { Top = 0, Left = 1, Right = 2, Bottom = 3 };
-
-// Controls the visibility of tabs in this notebook
-enum NotebookTabVisibility : int {
-    // Show all tabs
-    AllTabs = 0,
-
-    // Only show tabs containing splits that are live
-    LiveOnly = 1,
-};
-
 using TabVisibilityFilter = std::function<bool(const NotebookTab *)>;
 
 class Notebook : public BaseWidget