*Most* of the properties that were verified here were already verified
by the xpath parser before. I have not found any evidence that other
browsers do the remaining checks. There are web platform tests that
expect contradicting behavior (which pass in other browsers).
Additionally, this change switches `xpath` to use `markup5ever` instead
of `html5ever` - this is a drop-in replacement. I thought I did this as
part of https://github.com/servo/servo/pull/39546 but apparently the
change got lost in the rebasing.
Testing: A new web platform test starts to pass.
Fixes https://github.com/servo/servo/issues/39442
Part of #34527
cc @minghuaw
---------
Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>
XPath (and, in the future, XSLT) is only loosely coupled to `script`. As
`script` is already very large, I'd like to move the xpath parser and
evaluator into a seperate crate. Doing so allows us to iterate on it
more easily, without having to recompile `script`. Abstracting over the
concrete DOM implementation could also allow us to write some more
comprehensive unit tests.
Testing: Covered by existing web platform tests
Part of https://github.com/servo/servo/issues/34527
Fixes https://github.com/servo/servo/issues/39551
---------
Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>
