UI improvement Phase 1

- Simplified theme/style settings and corrected UI styles
- Move «Add To Library» button from toolbar to be simple  to find/press
it
- Toolbar in chapter list with sort/filtration
- library/catalog layout fixes

app/src/main/res/layout/activity_main.xml

@@ -1,18 +1,18 @@
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    android:gravity="center"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    android:gravity="center">
 
     <include
         android:id="@+id/toolbar"
-        layout="@layout/toolbar"/>
+        layout="@layout/toolbar" />
 
     <!-- the layout which will contain (host) the drawerLayout -->
     <FrameLayout
-        android:layout_below="@id/toolbar"
         android:id="@+id/drawer_container"
         android:layout_width="match_parent"
-        android:layout_height="match_parent">
+        android:layout_height="match_parent"
+        android:layout_below="@id/toolbar">
 
         <!-- the layout which will be the content of the activity (which will be hosted inside the drawer (NOT the list of the drawer)) -->
         <FrameLayout