Carry the linked nodes across Monitor jumps and clarify PBS web links

- A jump between Monitors carries the Monitors the source links, and the destination offers them in one dialog with a checkbox each
- The offer is not repeated in the same browser session after choosing Not now, and disappears once every node is known
- A Proxmox Backup Server without a Monitor is shown as its web interface, with its own icon
- The linked nodes form follows the edit-mode contrast rule, with a blue Add button
- New texts translated into all languages

AppImage/messages/en/common.json

@@ -6583,6 +6583,10 @@
     "backTo": "Back to {name}",
     "cameFromTitle": "Add Monitor node?",
     "cameFromBody": "Add {name} to the linked nodes of this Monitor.",
-    "notNow": "Not now"
+    "notNow": "Not now",
+    "knownTitle": "Add linked nodes?",
+    "knownBody": "{name} links these Monitors. Choose the ones to add to this Monitor.",
+    "addSelected": "Add selected",
+    "pbsWebInterface": "PBS web interface"
   }
 }