Add SVG icon for GTT map and update admin menu icon reference

Author: dkastl

config/icon_source.yml

@@ -0,0 +1,2 @@
+- name: gtt-map
+  svg: map

init.rb

@@ -42,7 +42,8 @@
   menu :admin_menu,
     :gtt_map_layers,
     { controller: 'gtt_map_layers', action: 'index' },
-    caption: :'map_layer.plural', html: { class: 'icon icon-gtt-map' }
+    caption: :'map_layer.plural', html: { class: 'icon icon-gtt-map' },
+    :icon => 'gtt-map', :plugin => :redmine_gtt
 end
 
 # Register MIME Types

src/styles/images/icons.svg

@@ -139,10 +139,12 @@ div.ol-rotate {
 // map.png icon as data URI
 $data-uri: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAK2SURBVBgZBcHLjxN1AADg79eZttvddttll+WxIGrAV4QYTbxoYsSLgjc5arx68qCGf8G7J+NBEg8e9GqURDEmEiOJAWNUwIi8sryWDbSdmc60Mx2/Lxw78caZ1fXVo1EUAYAAACAIgICymrt/7/6P8er66tHPPzklNIJyPgNAENRqAWSzBEFdN9TzWq3y0ckPj8ZRFKmUwuxL6fcXrJzJbJ18xFKv6/LlX1xMP3Nra6jXW3Z3eyiKm0Zp7t1jtWYcaQAMh9uGT7eMkkR2+m9JcluSJEJxQTEZm2Rj00liMkmUeSqEOYI4APr9ndQzi+/v4OPz2m+tWd+zV2d2xaQ8pDfoaUUNcbMlyXIhFAgaQDAcDiXJ2MP1ymilNPn6X6q5OvvZrEhk49SsyBR5alpkQqhBDNDvr1PPDPrLhu89Y+XTbeUre7TXCo9MtzW7+y22I81W0zibYkSgQQB5XkiTzHA0NF6qPHiC/Iv/1FWuMf1WPklMi1SeJubTVABBHACdzkB3OdVfXgbNtx/V+eCsuDpg7+pf8s7ERvcP7daW6eSaqPGOgDgAxsNUkhRI/bZ5x41Zw66DlSdPXbZ5PLUr+kYx+slg8Yj2uW1hNRPQEIKA5cFuFgZ+z0rXpk2DwU53XjtgX7xisrXXoDuycX1B54dLbrQqdbMFYqjr2rmbV13YvKTb7cnzXJKkkqLw61MNh7+6Ijl/3eZK0+3nHzdqBvtbbRAHZGVqq5ppt7qWOn15MdVd6Or/ed2+W5lWkwfPHnbzsZZ2e8HStKCuQUwQQkPPsknItKuOxdC16+I9rc2Jqy8dURxMvHz2oX/27xa1m5irZqWAuCwrVVXZ2PGcjVUCCMIhvMpaCCC8OPdCNBMttESNSDWvlFUlvHni+Hc719dej5oxggAIAAAIAIGyrGzd3Tr9P5JrNp8Zt4rCAAAAAElFTkSuQmCC');
 
-#admin-menu a.gtt,
-#admin-menu a.gtt-tile-sources,
-.icon-gtt-map {
-  background-image: $data-uri;
+/** SVG icons */
+.icon-gtt-map:not(:has(svg)) { background-image: $data-uri; }
+
+// to make webpack copy the SVG file to the output directory
+.dummy-svg-sprite {
+  background-image: url('../images/icons.svg');
 }
 
 div.usermap h3 {