For #6758 - Part 3: Add TopSiteStorage wrapper around AC's TopSiteStorage

This follows the existing pattern around TabCollectionStorage.

app/src/main/java/org/mozilla/fenix/components/Core.kt

@@ -192,6 +192,8 @@ class Core(private val context: Context) {
 
     val tabCollectionStorage by lazy { TabCollectionStorage(context, sessionManager) }
 
+    val topSiteStorage by lazy { TopSiteStorage(context) }
+
     val permissionStorage by lazy { PermissionStorage(context) }
 
     val webAppManifestStorage by lazy { ManifestStorage(context) }

app/src/main/java/org/mozilla/fenix/components/TopSiteStorage.kt

@@ -0,0 +1,41 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.components
+
+import android.content.Context
+import androidx.lifecycle.LiveData
+import mozilla.components.feature.top.sites.TopSite
+import mozilla.components.feature.top.sites.TopSiteStorage
+import org.mozilla.fenix.test.Mockable
+
+@Mockable
+class TopSiteStorage(private val context: Context) {
+    var cachedTopSites = listOf<TopSite>()
+
+    private val topSiteStorage by lazy {
+        TopSiteStorage(context)
+    }
+
+    /**
+     * Adds a new [TopSite].
+     */
+    fun addTopSite(title: String, url: String) {
+        topSiteStorage.addTopSite(title, url)
+    }
+
+    /**
+     * Returns a [LiveData] list of all the [TopSite] instances.
+     */
+    fun getTopSites(): LiveData<List<TopSite>> {
+        return topSiteStorage.getTopSites()
+    }
+
+    /**
+     * Removes the given [TopSite].
+     */
+    fun removeTopSite(topSite: TopSite) {
+        topSiteStorage.removeTopSite(topSite)
+    }
+}