Upgrading VTU to v1: Fix requirement_form_spec with latest `@vue/test-utils`

What does this MR do

This MR is part of &3856 (closed) and &5102

This MR fixes "wrong" test, when we were setting drawerOpen from true to true... triggering watcher because of $forceUpdate inside vue-test-utils We switch check for real world from false to true to test real behavior

Additional changes "while we are here":

• unify nextTick as per gitlab-org/frontend/rfcs#47 (closed)