Set sketchbook list item height to 30px (#1146)

Author: francescospissu

arduino-ide-extension/src/browser/style/index.css

@@ -125,4 +125,4 @@ button.theia-button.main {
   background-attachment: fixed;
   background-position: center;
   transition: opacity 0.8s;
-}
+}

arduino-ide-extension/src/browser/style/sketchbook.css

@@ -49,6 +49,10 @@
 
 }
 
+#arduino-sketchbook-tree-widget .theia-TreeNode {
+  line-height: 30px;
+}
+
 #arduino-sketchbook-tree-widget .theia-TreeNodeSegmentGrow {
   flex: 1;
 }