fix: made some missing texts translatable

BREAKING CHANGE: locales without the new fields will display the field name

client/public/locales/en/builder.json

@@ -257,7 +257,9 @@
         "heading": "Layout",
         "tooltip": {
           "reset-layout": "Reset Layout"
-        }
+        },
+        "main": "Main",
+        "sidebar": "Sidebar"
       },
       "links": {
         "bugs-features": {
@@ -278,7 +280,8 @@
         "global": {
           "date": {
             "primary": "Date",
-            "secondary": "Date format to use across the app"
+            "secondary": "Date format to use across the app",
+            "prefix": "Eg."
           },
           "heading": "Global",
           "language": {