add prometheus service widget

public/locales/en/common.json

@@ -521,5 +521,10 @@
     "pterodactyl": {
         "servers": "Servers",
         "nodes": "Nodes"
+    },
+    "prometheus": {
+        "targets_up": "Targets Up",
+        "targets_down": "Targets Down",
+        "targets_total": "Total Targets"
     }
 }