Add supprot for .NET 9 Static assets to DotVVM resources

[holajan]

In .NET 9 is new feature Static assets.

You can replace UseStaticFiles to MapStaticAssets. But it is only part of this feature.
The main goal is to use fingerprinting and generated .gz and .br assets (with .staticwebassets.endpoints.json in debug enviroment).

You can use new @assets property (In Blazor apps) or link tag helpers (MVC & Razor Pages apps) to resolve the assets fingerprinted file names and <ImportMap /> component or <script type="importmap"></script> for JavaScript modules. There is no such functionality for DotVVM apps.
It needs to be added in DotVVM resources registration in UrlResourceLocation or similar class.

Please add this support.

[exyi]

Ok, I like the idea and I tried to look into it. However, I did not find a reasonable way to add the support. As far as I understand it, we need to find the ResourceAssetCollection somewhere. Razor pages use an internal API for this: https://source.dot.net/#Microsoft.AspNetCore.Mvc.RazorPages/Builder/PageActionEndpointConventionBuilderResourceCollectionExtensions.cs,90ec282fad908e18, so best I currently have is this:

1. Obtain the ResourceAssetCollection:

var resolverT = Type.GetType("Microsoft.AspNetCore.Components.Endpoints.ResourceCollectionResolver, Microsoft.AspNetCore.Components.Endpoints")!;
var resolver = Activator.CreateInstance(resolverT, args: [ ep ]); 
var anyFlags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
var resourceCollection = (ResourceAssetCollection)resolverT.GetMethod("ResolveResourceCollection", anyFlags)!.Invoke(resolver, [null])!;

2. store it somewhere (static variable)
3. Add a resource location which can use this:

class AssetResourceLocation(string url): IResourceLocation
{
    public string GetUrl(IDotvvmRequestContext context, string name)
    {
        ResourceAssetCollection assets = ???;
        var versionedUrl = assets[url];
        if (versionedUrl is null || versionedUrl == url)
        {
            throw new Exception($"Asset {url} does not exist?");
        }

        return "/" + versionedUrl;
    }
}

4. You can then add resources with config.Resources.Register("something", new ScriptModuleResource(new AssetResourceLocation(assets, "path/to/something.js")));

However, it would be great to integrate it beyond this - support it TranslateVirtualPath, so all static URL can benefit. Do you have any idea if there is a better API?