Add tests for 'quarter' unit in Intl.RelativeTimeFormat#format

Bug: v8:7869
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I03077d5d89e1b9e459af0c31b5bf7378d9c4a1f0
Reviewed-on: https://chromium-review.googlesource.com/1244758
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56249}