Adding rescaling support to WMFMediaDataEncoder
This patch adds rescaling support to WMFMediaDataEncoder.
It fixes distorted Images when rescaling.
Furthermore, wpt tests are added to find similar errors on other platforms.
Includes revisions by chunmin
Differential Revision: https://phabricator.services.mozilla.com/D225445
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1921623
gecko-commit: 4cb52934d7d78871ce24accde75fee8a67108373
gecko-reviewers: chunmin