Refactor Workspace Loading / Processing code.

There are no behavioral changes (other than we no longer are recycling
objects while processing workspace items), but this refactor will setup
the next change to load the first workspace page before other workspace
pages.

Bug: 251502424
Test: Workspace, app widgets, and containers loaded properly.
Change-Id: I437aab40000d841d7fcc4380d05ab4a8f5d5c2ad

src/com/android/launcher3/model/ModelDelegate.java

@@ -80,10 +80,29 @@ public class ModelDelegate implements ResourceBasedOverride {
     }
 
     /**
-     * Load delegate items if any in the data model
+     * Load hot seat items if any in the data model
      */
     @WorkerThread
-    public void loadItems(UserManagerState ums, Map<ShortcutKey, ShortcutInfo> pinnedShortcuts) { }
+    public void loadHotseatItems(UserManagerState ums,
+            Map<ShortcutKey, ShortcutInfo> pinnedShortcuts) { }
+
+    /**
+     * Load all apps items if any in the data model
+     */
+    @WorkerThread
+    public void loadAllAppsItems(UserManagerState ums,
+            Map<ShortcutKey, ShortcutInfo> pinnedShortcuts) { }
+
+    /**
+     * Load widget recommendation items if any in the data model
+     */
+    @WorkerThread
+    public void loadWidgetsRecommendationItems() { }
+
+    /**
+     * Marks the ModelDelegate as active
+     */
+    public void markActive() { }
 
     /**
      * Load String cache