add icons to kerb fields, tweak label, drop from specialized presets

specialized presets should be switched using the preset selector, no need to duplicate that as a combo box. this effectively reverts https://github.com/openstreetmap/iD/issues/6360

(re icons, see also https://github.com/openstreetmap/id-tagging-schema/pull/1077#issuecomment-1966247784)

also remove duplicates of translatable strings

data/fields/kerb.json

@@ -29,5 +29,11 @@
                 "description": "Some sort of curb is present at this location, unknown whether it is raised, lowered, flush etc."
             }
         }
+    },
+    "icons": {
+        "raised": "temaki-kerb-raised",
+        "lowered": "temaki-kerb-lowered",
+        "flush": "temaki-kerb-flush",
+        "rolled": "temaki-kerb-rolled"
     }
 }

data/fields/kerb/kerb_barrier.json

@@ -1,25 +1,14 @@
 {
     "key": "kerb",
     "type": "combo",
-    "label": "Curb",
-    "strings": {
-        "options": {
-            "flush": {
-                "title": "Flush",
-                "description": "A dropped curb which is level with the surrounding area."
-            },
-            "lowered": {
-                "title": "Lowered",
-                "description": "A dropped curb which can be used by wheelchair users, not higher than a few centimeters."
-            },
-            "raised": {
-                "title": "Raised",
-                "description": "A raised curb which can't easily be used by wheelchair users, higher than a few centimeters."
-            },
-            "rolled": {
-                "title": "Rolled",
-                "description": "A raised curb with a rounded edge which makes it easier to use for cars or bicycles, but not for wheelchairs."
-            }
-        }
-    }
+    "label": "Type",
+    "stringsCrossReference": "{kerb}",
+    "options": [
+        "flush",
+        "lowered",
+        "raised",
+        "rolled"
+    ],
+    "autoSuggestions": false,
+    "iconsCrossReference": "{kerb}"
 }

data/presets/barrier/kerb/flush.json

@@ -1,9 +1,5 @@
 {
     "icon": "temaki-kerb-flush",
-    "fields": [
-        "kerb/kerb_barrier",
-        "{barrier/kerb}"
-    ],
     "geometry": [
         "vertex",
         "line"

data/presets/barrier/kerb/lowered.json

@@ -1,7 +1,6 @@
 {
     "icon": "temaki-kerb-lowered",
     "fields": [
-        "kerb/kerb_barrier",
         "{barrier/kerb}",
         "kerb/height"
     ],

data/presets/barrier/kerb/raised.json

@@ -1,7 +1,6 @@
 {
     "icon": "temaki-kerb-raised",
     "fields": [
-        "kerb/kerb_barrier",
         "{barrier/kerb}",
         "kerb/height"
     ],

data/presets/barrier/kerb/rolled.json

@@ -1,7 +1,6 @@
 {
     "icon": "temaki-kerb-rolled",
     "fields": [
-        "kerb/kerb_barrier",
         "{barrier/kerb}",
         "kerb/height"
     ],