split off regional preset for post boxes in US

which allows to move "drive_through" field to "moreFields" by default

data/presets/amenity/post_box.json

@@ -3,7 +3,6 @@
     "fields": [
         "operator",
         "collection_times",
-        "drive_through",
         "ref"
     ],
     "moreFields": [
@@ -12,7 +11,7 @@
         "brand",
         "colour",
         "covered",
-        "gnis/feature_id-US",
+        "drive_through",
         "height",
         "indoor",
         "level",
@@ -46,7 +45,8 @@
     ],
     "locationSet": {
         "exclude": [
-            "gb"
+            "gb",
+            "us"
         ]
     },
     "name": "Mail Drop Box"

data/presets/amenity/post_box/post_box-GB.json

@@ -6,11 +6,9 @@
         ]
     },
     "fields": [
-        "operator",
-        "collection_times",
+        "{amenity/post_box}",
         "post_box/type",
-        "royal_cypher",
-        "ref"
+        "royal_cypher"
     ],
     "moreFields": [
         "{amenity/post_box}",

data/presets/amenity/post_box/post_box-US.json

@@ -0,0 +1,24 @@
+{
+    "icon": "temaki-post_box",
+    "locationSet": {
+        "include": [
+            "us"
+        ]
+    },
+    "fields": [
+        "{amenity/post_box}",
+        "drive_through"
+    ],
+    "moreFields": [
+        "{amenity/post_box}",
+        "gnis/feature_id-US"
+    ],
+    "geometry": [
+        "point",
+        "vertex"
+    ],
+    "tags": {
+        "amenity": "post_box"
+    },
+    "name": "{amenity/post_box}"
+}