Add Config class for Ziggy configuration management (dynamic configuration)

[thaqebon]

Summary

• Introduced a Config class to manage Ziggy configuration.
• Added static set(), get() and absolute() methods for default configuration.
• Updated Route and Router classes to use the new Config class.
• Added tests to ensure the config behavior is consistent and reliable.

Purpose

The main goal of this PR is to allow dynamic configuration of Ziggy at runtime by setting a config getter:

 // Inertia example
ZiggyConfig.set(() => usePage().props.ziggy);
 // DOM-based config
ZiggyConfig.set(() => JSON.parse(document.getElementById('ziggy-routes-json').textContent));

// Set default absolute flag
ZiggyConfig.absolute(false)

This makes Ziggy more flexible by allowing dynamic configuration instead of relying on a static one.

[bakerkretzmar]

Thanks a lot for the PR, and for your patience! This is really interesting but I think I'm going to pass for now. It's a lot of new code to introduce and I'm not sure that this pattern is super common or necessarily something we want to push people towards.

I can see how it could be helpful to eventually have something a bit more polished than Ziggy.location = '...' in Ziggy to handle updating configuration over time, especially for Inertia. If we do go down that road though I think I would want to lean towards something that updates it when it changes, something like route().configure({ ... }) to pass in new options, as opposed to fetching it dynamically on every route() call. Not sure though.