[5.x] Add support for public properties to PathDataManager

[marcorieser]

This PR adds support for accessing public properties on plain objects (non-augmentable / non-arrayaccess).

Backstory:
In the Statamic Livewire addon, I've added support for computed properties. Objects returned from there are not always augmentable objects. So I thought it would be nice to be able to process those objects in Antlers, too, meaning calling public methods and accessing public properties (on non-augmentable / non-arrayaccess objects).

{{ livewire:computed:property:nested_path:plain_object:public_method }}
{{ livewire:computed:property:nested_path:plain_object:public_property }}

class Dummy
{
    public string $public_property = 'Public Property';

    public function publicMethod()
    {
        return 'Public Method';
    }
}

I started iterating the path segments and handling all the different types of values/objects myself, but then realized Statamic already can do that (but didn't find the correct place where this is handled in the runtime parser). I had a quick talk with Duncan and John Koster on how to handle that. We (basically John 😅) figured out, it's the PathDataManager. This works perfectly, but it currently doesn't check for public properties on objects.

https://discord.com/channels/489818810157891584/1360647492701519963

[jasonvarga]

Please edit the description to explain the PR.

[marcorieser]

Sure, will do. It's currently just a draft.