Add area fill selector (wireframe/partial/full) to map data panel

also:
* style dark tooltips with shortcut keys
* use uppercase for shortcut keys

data/core.yaml

@@ -242,8 +242,9 @@ en:
   map_data:
     title: Map Data
     description: Map Data
-    show_features: Show Features
-    show_layers: Show Layers
+    show_features: Show Map Features
+    show_layers: Show Data Layers
+    fill_area: Fill Areas
   feature:
     points:
       description: Points
@@ -281,6 +282,16 @@ en:
     others:
       description: Others
       tooltip: "Everything Else"
+  area_fill:
+    wireframe:
+      description: No Fill (Wireframe)
+      tooltip: "Enabling wireframe mode makes it easy to see the background imagery."
+    partial:
+      description: Partial Fill
+      tooltip: "Areas are drawn with fill only around their inner edges. (Recommended for beginner mappers)"
+    full:
+      description: Full Fill
+      tooltip: "Areas are drawn fully filled."
   restore:
     heading: You have unsaved changes
     description: "Do you wish to restore unsaved changes from a previous editing session?"