Add translatable strings to basin type field (#710)

data/fields/basin.json

@@ -1,5 +1,13 @@
 {
     "key": "basin",
     "type": "combo",
-    "label": "Type"
+    "label": "Type",
+    "strings": {
+        "options": {
+            "detention": "Detention",
+            "evaporation": "Evaporation",
+            "infiltration": "Infiltration",
+            "retention": "Retention"
+        }
+    }
 }