Added layer control to map to allow each geozone display to be toggled on/off

Note we're adding a `name` property to the geozones investments sidebar
map even if we don't render the geozones in the map, in order to
simplify the JavaScript function `geozoneLayers`.

app/components/admin/geozones/index_component.rb

@@ -25,7 +25,8 @@ class Admin::Geozones::IndexComponent < ApplicationComponent
         {
           outline_points: geozone.outline_points,
           color: geozone.color,
-          headings: [link_to(geozone.name, edit_admin_geozone_path(geozone))]
+          headings: [link_to(geozone.name, edit_admin_geozone_path(geozone))],
+          name: geozone.name
         }
       end
     end

app/components/budgets/investments/map_component.rb

@@ -27,7 +27,8 @@ class Budgets::Investments::MapComponent < ApplicationComponent
       [
         {
           outline_points: heading.geozone.outline_points,
-          color: heading.geozone.color
+          color: heading.geozone.color,
+          name: heading.name
         }
       ]
     end

app/components/budgets/map_component.rb

@@ -27,10 +27,15 @@ class Budgets::MapComponent < ApplicationComponent
         {
           outline_points: geozone.outline_points,
           color: geozone.color,
-          headings: budget.headings.where(geozone: geozone).map do |heading|
+          headings: geozone_headings(geozone).map do |heading|
             link_to heading.name, budget_investments_path(budget, heading_id: heading.id)
-          end
+          end,
+          name: geozone_headings(geozone).map(&:name).join(", ")
         }
       end
     end
+
+    def geozone_headings(geozone)
+      budget.headings.where(geozone: geozone)
+    end
 end