test: add upstream test cases to encoding

Refs: https://github.com/web-platform-tests/wpt/pull/25988
Refs: https://github.com/web-platform-tests/wpt/pull/26158

PR-URL: https://github.com/nodejs/node/pull/35794


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>