rename book_id in po table to booking_id to perform ORM relantionship

added relationship between booking and po
updated settings shows for different role
added function to display po for admin

app/Http/Controllers/BookingController.php

@@ -427,6 +427,13 @@ class BookingController extends Controller
         return response()->json(['message'=>'Success'],200);
     }
 
+    public function showPurchaseOrder($id){
+        $booking = Booking::where('id',$id)->first();
+        $user_po = $booking->purchaseOrder()->first();
+
+        return response()->json(['po_path'=> $user_po],200);
+    }
+
     public function delete(Booking $book_id)
     {
         $booking = Booking::where('user_id', Auth::user())->where('id', $book_id)->firstOrFail();