Move calendar validation out of ParseTemporalCalendarString
Spec PR https://github.com/tc39/proposal-temporal/pull/1954

Bug: v8:11544
Change-Id: I4dbfcba1a9f5940d5692547b7ea212ebe45ca341
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3835265Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82546}