Add translatable strings to bollard type field (#702)

Author: kjonosm

data/fields/bollard.json

@@ -1,5 +1,14 @@
 {
     "key": "bollard",
     "type": "combo",
-    "label": "Type"
+    "label": "Type",
+    "strings": {
+        "options": {
+            "fixed": "Fixed Bollard",
+            "flexible": "Flexible Bollard",
+            "foldable": "Foldable Bollard",
+            "removable": "Removable Bollard",
+            "rising": "Rising Bollard"
+        }
+    }
 }