Added Nav Bar and Refactor some activities to fragments

- Added a nav bar to go to customer chat and staff profile
- refactored the activities for pets, suppliers, services and it's detailed activates to make the newly added nav bar to work on all screens.

TODO:
- add functionalities to profile and chat fragments
- change theme of app to stay consistent with desktop app
- change text so it uses String.xml values

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

@@ -5,7 +5,7 @@
     android:id="@+id/main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".activities.AppointmentActivity">
+    tools:context=".activities.listactivities.AppointmentActivity">
 
     <TextView
         android:id="@+id/textView3"