enh: Move ember-table query params init to mixin

app/controllers/events/list.js

@@ -1,14 +1,9 @@
 import Controller from '@ember/controller';
 import { computed, action } from '@ember/object';
+import EmberTableControllerMixin from 'open-event-frontend/mixins/ember-table-controller';
+
+export default class extends Controller.extend(EmberTableControllerMixin) {
 
-export default class extends Controller {
-  queryParams = ['page', 'per_page'];
-  page = 1;
-  per_page = 10;
-  search = null;
-  sort_dir = null;
-  sort_by = null;
-  sorts = [];
   @computed()
   get columns() {
     return [

app/mixins/ember-table-controller.js

@@ -0,0 +1,11 @@
+import Mixin from '@ember/object/mixin';
+
+export default Mixin.create({
+  queryParams : ['page', 'per_page', 'search', 'sort_dir', 'sort_by'],
+  page        : 1,
+  per_page    : 10,
+  search      : null,
+  sort_dir    : null,
+  sort_by     : null,
+  sorts       : []
+});

app/routes/events/list.js

@@ -1,8 +1,8 @@
 import Route from '@ember/routing/route';
 import { action } from '@ember/object';
 import moment from 'moment';
-import EmberTableMixin from 'open-event-frontend/mixins/ember-table';
-export default class extends Route.extend(EmberTableMixin) {
+import EmberTableRouteMixin from 'open-event-frontend/mixins/ember-table-route';
+export default class extends Route.extend(EmberTableRouteMixin) {
 
   titleToken() {
     switch (this.get('params.event_state')) {

tests/unit/mixins/ember-table-controller-test.js

@@ -0,0 +1,12 @@
+import EmberObject from '@ember/object';
+import EmberTableControllerMixin from 'open-event-frontend/mixins/ember-table-controller';
+import { module, test } from 'qunit';
+
+module('Unit | Mixin | ember-table-controller', function() {
+  // Replace this with your real tests.
+  test('it works', function(assert) {
+    let EmberTableControllerObject = EmberObject.extend(EmberTableControllerMixin);
+    let subject = EmberTableControllerObject.create();
+    assert.ok(subject);
+  });
+});

tests/unit/mixins/ember-table-route-test.js

@@ -0,0 +1,12 @@
+import EmberObject from '@ember/object';
+import EmberTableRouteMixin from 'open-event-frontend/mixins/ember-table-route';
+import { module, test } from 'qunit';
+
+module('Unit | Mixin | ember-table-route', function() {
+  // Replace this with your real tests.
+  test('it works', function(assert) {
+    let EmberTableRouteObject = EmberObject.extend(EmberTableRouteMixin);
+    let subject = EmberTableRouteObject.create();
+    assert.ok(subject);
+  });
+});