Implement the accessKeyLabel IDL attribute per the HTML spec.
We mimic Chromium's behavior and treat the accesskey attribute value as
a single key rather than splitting on whitespace, since no browser
besides IE/Edge implemented the spec's splitting approach.
See https://github.com/whatwg/html/issues/3769
When an element's ID is removed we only want to remove it from
`m_potentially_named_elements` if it is not also considered a
potentially named element due to it's name content attribute.
This change imports the WPT html/dom/aria-attribute-reflection.html test
into being an in-tree test — and deletes the related existing test
from https://github.com/LadybirdBrowser/ladybird/commit/a924e8747a4
previously “ported” from the WPT with changes to run under our (non-WPT)
in-tree test harness.
And here's the wild part: instead of cloning WPT tests, import the
relevant WPT tests that this fixes into our own test suite.
This works by adding a small Ladybird-specific callback in
resources/testharnessreport.js (which is what that file is meant for!)
Note that these run as text tests, and so they must signal the runner
when they are done. Tests using the "usual" WPT harness should just
work, but tests that do something more freestyle will need manual
signaling if they are to be imported.
I've also increased the test timeout here from 30 to 60 seconds,
to accommodate the larger WPT-style tests.
