Merge branch '247105-turn-helpers-startup_css_helper-usage-path-to-a-friendly-one' into 'master'

Turn startup css helper path to the aliased one

See merge request gitlab-org/gitlab!43997

app/assets/javascripts/behaviors/autosize.js

 import Autosize from 'autosize';
-import { waitForCSSLoaded } from '../helpers/startup_css_helper';
+import { waitForCSSLoaded } from '~/helpers/startup_css_helper';
 
 document.addEventListener('DOMContentLoaded', () => {
   waitForCSSLoaded(() => {

app/assets/javascripts/pages/projects/graphs/charts/index.js

-import Vue from 'vue';
 import { GlColumnChart } from '@gitlab/ui/dist/charts';
-import { waitForCSSLoaded } from '../../../../helpers/startup_css_helper';
+import Vue from 'vue';
+import { waitForCSSLoaded } from '~/helpers/startup_css_helper';
 import { __ } from '~/locale';
 import CodeCoverage from '../components/code_coverage.vue';
 import SeriesDataMixin from './series_data_mixin';

spec/frontend/helpers/startup_css_helper_spec.js

-import { waitForCSSLoaded } from '../../../app/assets/javascripts/helpers/startup_css_helper';
+import { waitForCSSLoaded } from '~/helpers/startup_css_helper';
 
 describe('waitForCSSLoaded', () => {
   let mockedCallback;