New cache system

Refactoring
Separation into libraries

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

@@ -5,19 +5,17 @@
     android:layout_height="match_parent">
 
     <com.google.android.material.appbar.AppBarLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
         android:layout_marginStart="16dp"
         android:layout_marginEnd="16dp"
         android:layout_marginBottom="8dp"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
         android:background="@android:color/transparent"
         app:elevation="0dp">
 
         <com.google.android.material.appbar.CollapsingToolbarLayout
             android:layout_width="match_parent"
-            android:background="@drawable/toolbar_background"
             android:layout_height="wrap_content"
-            android:layout_marginTop="8dp"
             app:layout_scrollFlags="scroll|enterAlways">
 
             <include layout="@layout/toolbar" />
@@ -31,7 +29,8 @@
         android:id="@+id/progressBar"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_gravity="center" />
+        android:layout_gravity="center"
+        android:visibility="gone" />
 
     <include
         layout="@layout/no_items_view"