Removed css files

Removed datatables cssfile
Removed sb admin css file
Load sb admin css file via cdn

src/main/resources/templates/fragments/admin.html

@@ -51,7 +51,7 @@
 
         <link href="https://use.fontawesome.com/releases/v5.6.3/css/all.css" rel="stylesheet">
         <link href="http://fonts.googleapis.com/css?family=Roboto:400,700,300" rel="stylesheet" type="text/css">
-        <link th:href="@{/css/sb-admin-2.css}" href="../../static/css/sb-admin-2.css" rel="stylesheet">
+        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/startbootstrap-sb-admin-2/4.0.7/css/sb-admin-2.min.css" integrity="sha512-FXgL8f6gtCYx8PjODtilf5GCHlgTDdIVZKRcUT/smwfum7hr4M1ytewqTtNd9LK4/CzbW4czU6Tr3f3Xey6lRg==" crossorigin="anonymous" />
 
         <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"
             integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">