Moved menubar to own file

src/main.py

@@ -1,24 +1,11 @@
 import flet as ft
 from MealBuilder import builder
 from MealSelector import selector
+from models.MenuBar import create_menubar
 
 
 def main(page: ft.Page):
-    main_appbar = ft.AppBar(
-        title=ft.Text("Meal Picker"),
-        bgcolor=ft.Colors.GREEN_700,
-        center_title=False,
-        actions=[
-            ft.PopupMenuButton(
-                items=[
-                    ft.PopupMenuItem(text="Meal Selector", on_click=lambda e: selector(page)),
-                    ft.PopupMenuItem(text="Meal Builder", on_click=lambda e: builder(page)),
-                ]
-            )
-        ]
-    )
-
-    page.appbar = main_appbar
+    page.appbar = create_menubar(page, selector, builder)
 
     page.add(ft.Pagelet(
             content = ft.Text("Welcome to Meal Picker! Please select an option from the menu above to get started.")