Add Dance Styles field, change icon to music notes

(re: https://github.com/openstreetmap/iD/pull/4846#issuecomment-370317305)

data/presets.yaml

@@ -402,6 +402,9 @@ en:
         types:
           'cycleway:left': Left side
           'cycleway:right': Right side
+      dance/style:
+        # 'dance:style=*'
+        label: Dance Styles
       date:
         # date=*
         label: Date
@@ -3618,10 +3621,10 @@ en:
         # 'terms: ballroom,jive,swing,tango,waltz'
         terms: '<translate with synonyms or related terms for ''Dance Hall'', separated by commas>'
       leisure/dancing_school:
-        # leisure=dance, dance:teaching=yes
-        name: Dancing School
+        # 'leisure=dance, dance:teaching=yes'
+        name: Dance School
         # 'terms: jive,swing,tango,waltz,dance teaching'
-        terms: '<translate with synonyms or related terms for ''Dancing School'', separated by commas>'
+        terms: '<translate with synonyms or related terms for ''Dance School'', separated by commas>'
       leisure/dog_park:
         # leisure=dog_park
         name: Dog Park

data/presets/fields.json

@@ -548,6 +548,11 @@
                 }
             }
         },
+        "dance/style": {
+            "key": "dance:style",
+            "type": "semiCombo",
+            "label": "Dance Styles"
+        },
         "date": {
             "key": "date",
             "type": "check",

data/presets/fields/dance/style.json

@@ -0,0 +1,5 @@
+{
+    "key": "dance:style",
+    "type": "semiCombo",
+    "label": "Dance Styles"
+}

data/presets/presets.json

@@ -9425,12 +9425,13 @@
             "name": "Dance Hall"
         },
         "leisure/dancing_school": {
-            "icon": "school",
+            "icon": "music",
             "fields": [
                 "name",
                 "operator",
                 "address",
-                "opening_hours"
+                "opening_hours",
+                "dance/style"
             ],
             "geometry": [
                 "point",
@@ -9451,7 +9452,7 @@
                 "key": "leisure",
                 "value": "dance"
             },
-            "name": "Dancing School"
+            "name": "Dance School"
         },
         "leisure/dog_park": {
             "icon": "dog-park",

data/presets/presets/leisure/dancing_school.json

@@ -1,10 +1,11 @@
 {
-    "icon": "school",
+    "icon": "music",
     "fields": [
         "name",
         "operator",
         "address",
-        "opening_hours"
+        "opening_hours",
+        "dance/style"
     ],
     "geometry": [
         "point",
@@ -25,5 +26,5 @@
         "key": "leisure",
         "value": "dance"
     },
-    "name": "Dancing School"
+    "name": "Dance School"
 }

dist/locales/en.json

@@ -1703,6 +1703,9 @@
                         }
                     }
                 },
+                "dance/style": {
+                    "label": "Dance Styles"
+                },
                 "date": {
                     "label": "Date"
                 },
@@ -4526,7 +4529,7 @@
                     "terms": "ballroom,jive,swing,tango,waltz"
                 },
                 "leisure/dancing_school": {
-                    "name": "Dancing School",
+                    "name": "Dance School",
                     "terms": "jive,swing,tango,waltz,dance teaching"
                 },
                 "leisure/dog_park": {