Add gantry presets (#649)

* Add preset for `man_made=gantry`

* Add presets for `power=portal` and `crane:type=*`

Also added terms to Gantry preset and changed label from "Road Sign Structure" to "Gantry"

* Apply suggestions from code review

Co-authored-by: Martin Raifer <martin@raifer.tech>

* Add strucutre_power field

Also moved design to moreFields

* Add structure_power field to power=tower preset

Co-authored-by: Martin Raifer <martin@raifer.tech>

data/presets/power/portal.json

@@ -0,0 +1,29 @@
+{
+    "icon": "temaki-power",
+    "fields": [
+        "ref",
+        "operator",
+        "structure_power",
+        "material"
+    ],
+    "moreFields": [
+        "colour",
+        "design",
+        "height",
+        "line_management",
+        "manufacturer"
+    ],
+    "geometry": [
+        "vertex",
+        "line"
+    ],
+    "terms": [
+        "anchor gantry",
+        "gantry tower",
+        "h-frame tower"
+    ],
+    "tags": {
+        "power": "portal"
+    },
+    "name": "Anchor Portal"
+}

data/presets/power/tower.json

@@ -6,7 +6,8 @@
         "design",
         "height",
         "material",
-        "line_attachment"
+        "line_attachment",
+        "structure_power"
     ],
     "moreFields": [
         "line_management",