Add Recently Added and On Deck to Plex media browser (#39232)

tests/components/plex/mock_classes.py

@@ -346,6 +346,14 @@ class MockPlexLibrary:
         """Mock the sectionByID lookup."""
         return [x for x in self.sections() if x.key == section_id][0]
 
+    def onDeck(self):
+        """Mock an empty On Deck folder."""
+        return []
+
+    def recentlyAdded(self):
+        """Mock an empty Recently Added folder."""
+        return []
+
 
 class MockPlexLibrarySection:
     """Mock a Plex LibrarySection instance."""
@@ -381,6 +389,14 @@ class MockPlexLibrarySection:
                     if child.ratingKey == ratingKey:
                         return child
 
+    def onDeck(self):
+        """Mock an empty On Deck folder."""
+        return []
+
+    def recentlyAdded(self):
+        """Mock an empty Recently Added folder."""
+        return self.all()
+
     @property
     def type(self):
         """Mock the library type."""