Initialise component state in init() instead of constructor

This allows component state to be overridden via monkey-patch. ref #246

framework/core/js/admin/src/components/AppearancePage.js

@@ -5,9 +5,7 @@ import EditCustomCssModal from 'flarum/components/EditCustomCssModal';
 import saveSettings from 'flarum/utils/saveSettings';
 
 export default class AppearancePage extends Component {
-  constructor(...args) {
-    super(...args);
-
+  init() {
     this.primaryColor = m.prop(app.settings.theme_primary_color);
     this.secondaryColor = m.prop(app.settings.theme_secondary_color);
     this.darkMode = m.prop(app.settings.theme_dark_mode === '1');

framework/core/js/admin/src/components/EditCustomCssModal.js

@@ -3,9 +3,7 @@ import Button from 'flarum/components/Button';
 import saveSettings from 'flarum/utils/saveSettings';
 
 export default class EditCustomCssModal extends Modal {
-  constructor(...args) {
-    super(...args);
-
+  init() {
     this.customLess = m.prop(app.settings.custom_less || '');
   }
 

framework/core/js/admin/src/components/EditGroupModal.js

@@ -8,9 +8,7 @@ import Group from 'flarum/models/Group';
  * to create or edit a group.
  */
 export default class EditGroupModal extends Modal {
-  constructor(...args) {
-    super(...args);
-
+  init() {
     this.group = this.props.group || app.store.createRecord('groups');
 
     this.nameSingular = m.prop(this.group.nameSingular() || '');

framework/core/js/admin/src/components/PermissionGrid.js

@@ -6,9 +6,7 @@ import ItemList from 'flarum/utils/ItemList';
 import icon from 'flarum/helpers/icon';
 
 export default class PermissionGrid extends Component {
-  constructor(...args) {
-    super(...args);
-
+  init() {
     this.permissions = this.permissionItems().toArray();
   }