feat(settings): place the search bar at the top or the bottom

Add a search bar position setting and render the bar above the
results or below them, with window insets applied to match.

app/src/main/res/drawable/ic_manage_search.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M7,9H2V7h5v2zM7,12H2v2h5v-2zM20.59,19l-3.83,-3.83c-0.8,0.52 -1.74,0.83 -2.76,0.83 -2.76,0 -5,-2.24 -5,-5s2.24,-5 5,-5 5,2.24 5,5c0,1.02 -0.31,1.96 -0.83,2.75L22,17.59 20.59,19zM17,11c0,-1.65 -1.35,-3 -3,-3s-3,1.35 -3,3 1.35,3 3,3 3,-1.35 3,-3zM2,19h10v-2H2v2z" />
+</vector>