Use xpath query handler

[kblok]

closes #2085

[jnyrup]

Use 4 spaces instead of 2 🧹

[kblok]

ohhh just merged! Let's create a follow up PR

[jnyrup]

I'll create a PR right away

[kblok]

I have one ready to go :)

[jnyrup]

Suggestion:
Besides _defaultHandler, we don't need to store the internal handlers in separate fields as they are only used in the constructor to initialize _internalQueryHandlers.

By changing them from fields to private static creator methods, we can move initialization of _internalQueryHandlers to declaration and remove the then empty public constructor.

private readonly Dictionary<string, PuppeteerQueryHandler> _internalQueryHandlers = new()
{
    ["aria"] = AriaHandler(),
    ["pierce"] = PierceHandler(),
    ["text"] = TextQueryHandler(),
    ["xpath"] = XpathHandler(),
};