UX: Remove `hidden` from the `#discourse-modal` when the modal is shown

app/assets/javascripts/discourse/components/d-modal.js.es6

@@ -2,7 +2,7 @@ import { on } from "ember-addons/ember-computed-decorators";
 
 export default Ember.Component.extend({
   elementId: 'discourse-modal',
-  classNameBindings: [':modal', ':hidden', 'modalClass'],
+  classNameBindings: [':modal', 'modalClass'],
   attributeBindings: ['data-keyboard'],
 
   // We handle ESC ourselves
@@ -17,6 +17,7 @@ export default Ember.Component.extend({
     });
 
     this.appEvents.on('modal:body-shown', data => {
+      this.$().removeClass('hidden');
       if (data.title) {
         this.set('title', I18n.t(data.title));
       } else if (data.rawTitle) {

app/assets/javascripts/discourse/components/hide-modal-trigger.js.es6

@@ -1,6 +1,6 @@
 export default Ember.Component.extend({
   didInsertElement() {
     this._super();
-    $('#discourse-modal').modal('hide');
+    $('#discourse-modal').modal('hide').addClass('hidden');
   }
 });

app/assets/javascripts/discourse/templates/modal.hbs

@@ -1,4 +1,4 @@
-{{#d-modal modalClass=modalClass title=title}}
+{{#d-modal modalClass=modalClass title=title class="hidden"}}
   <div class="modal-outer-container">
     <div class="modal-middle-container">
       <div class="modal-inner-container">

app/assets/stylesheets/common/base/modal.scss

@@ -126,7 +126,7 @@
 
   }
 
-    &.hidden {
+  &.hidden {
     display: none;
   }