Create WPT tests for @page :left and :right.

There was no WPT coverage for this.

Remove corresponding parts from a legacy Blink test. Also remove the part about "@page :first", since we already have test coverage for "@page :first", in page-size-004-print.html, page-size-005-print.html and page-size-006-print.html in css/printing/

Change-Id: I91256bfffe99b48f8a5b3e5ffc0951fb8b15cd3f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5003846 Reviewed-by: Ian Kilpatrick ikilpatrick@chromium.org Commit-Queue: Morten Stenshorne mstensho@chromium.org Cr-Commit-Position: refs/heads/main@{#1219469}