[@container] Add tests for querying container-name only
Spec PR: w3c/csswg-drafts#11172
Bug: 40287550
Change-Id: Ibf930266cc78738c69e7629473a60cb9c5d67a57
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6003155
Commit-Queue: Rune Lillesveen futhark@chromium.org
Reviewed-by: Anders Hartvoll Ruud andruud@chromium.org
Cr-Commit-Position: refs/heads/main@{#1381100}