Convert hover-transform script tests to testharness test

Convert the existing js-test.js–based SVG hover-transform tests for
`<rect>`, `<text>`, `<image>`, `<clipPath>`, `<viewBox>`, and
`<foreignObject>` scenarios into the testharness test.

Bug: 41269302
Change-Id: I0e8aee6bbbc66f46b05c9cbbbba85a4599eb17c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6653467
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Ho Cheung <hocheung@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1476140}