refactor: Rename "server" to "bau" in common translation file

src/i18n/common/en.json

@@ -41,7 +41,7 @@
           "2": "From small combat machines to huge battleships, everything can be built."
         }
       },
-      "server": {
+      "bau": {
         "title": "Own Build Server",
         "description": "Every player gets their own build server to ensure maximum performance and minimal limitations with leading tools like FaWe or Axiom"
       },