isMiniScreen and showDesktopDragHandles centralized in class Utils

- a lot of same code everywhere in many files, this is against the
  concept "don't repeat yourself"

client/components/lists/list.js

@@ -117,22 +117,11 @@ BlazeComponent.extendComponent({
     });
 
     this.autorun(() => {
-      let showDesktopDragHandles = false;
-      currentUser = Meteor.user();
-      if (currentUser) {
-        showDesktopDragHandles = (currentUser.profile || {})
-          .showDesktopDragHandles;
-      } else if (window.localStorage.getItem('showDesktopDragHandles')) {
-        showDesktopDragHandles = true;
-      } else {
-        showDesktopDragHandles = false;
-      }
-
-      if (Utils.isMiniScreen() || showDesktopDragHandles) {
+      if (Utils.isMiniScreenOrShowDesktopDragHandles()) {
         $cards.sortable({
           handle: '.handle',
         });
-      } else if (!Utils.isMiniScreen() && !showDesktopDragHandles) {
+      } else if (!Utils.isMiniScreen() && !Utils.isShowDesktopDragHandles()) {
         $cards.sortable({
           handle: '.minicard',
         });
@@ -178,19 +167,6 @@ BlazeComponent.extendComponent({
   },
 }).register('list');
 
-Template.list.helpers({
-  showDesktopDragHandles() {
-    currentUser = Meteor.user();
-    if (currentUser) {
-      return (currentUser.profile || {}).showDesktopDragHandles;
-    } else if (window.localStorage.getItem('showDesktopDragHandles')) {
-      return true;
-    } else {
-      return false;
-    }
-  },
-});
-
 Template.miniList.events({
   'click .js-select-list'() {
     const listId = this._id;

client/components/lists/listHeader.jade

@@ -44,7 +44,7 @@ template(name="listHeader")
               a.js-add-card.fa.fa-plus.list-header-plus-icon(title="{{_ 'add-card-to-top-of-list'}}")
             a.fa.fa-navicon.js-open-list-menu(title="{{_ 'listActionPopup-title'}}")
           if currentUser.isBoardAdmin
-            if showDesktopDragHandles
+            if isShowDesktopDragHandles
               a.list-header-handle.handle.fa.fa-arrows.js-list-handle
 
 template(name="editListTitleForm")

client/components/lists/listHeader.js

@@ -122,18 +122,7 @@ BlazeComponent.extendComponent({
 Template.listHeader.helpers({
   isBoardAdmin() {
     return Meteor.user().isBoardAdmin();
-  },
-
-  showDesktopDragHandles() {
-    currentUser = Meteor.user();
-    if (currentUser) {
-      return (currentUser.profile || {}).showDesktopDragHandles;
-    } else if (window.localStorage.getItem('showDesktopDragHandles')) {
-      return true;
-    } else {
-      return false;
-    }
-  },
+  }
 });
 
 Template.listActionPopup.helpers({