Deduplicate `DependsOnResolutionFunc` and `KeyedDependsOnResolutionFunc`

[AGiorgetti]

Description

DependsOnResolutionFunc<TTarget> and KeyedDependsOnResolutionFunc<TTarget> in ServiceCollectionExtensions.KeyedService.cs share ~90% of their logic. The entire parameter resolution loop (matching dependsOn entries, resolving keyed vs non-keyed services) is duplicated. The only difference is the factory signature: Func<IServiceProvider, TTarget> vs Func<IServiceProvider, object?, TTarget>.

Suggested Fix

Extract the common resolution logic into a shared private method:

private static object[] ResolveConstructorArgs(
    IServiceProvider sp, Dependency[] dependsOn, ParameterInfo[] parameters)
{
    if (sp is not IKeyedServiceProvider keyed)
        throw new NotSupportedException(...);

    var args = new object[parameters.Length];
    for (int i = 0; i < args.Length; i++)
    {
        var p = parameters[i];
        var dep = Array.Find(dependsOn, d => d.ParameterName == p.Name);
        if (dep != null)
        {
            args[i] = dep.T == Dependency.DependencyType.KeyedServices
                ? keyed.GetRequiredKeyedService(p.ParameterType, dep.Value)
                : dep.Value;
        }
        else
        {
            args[i] = sp.GetRequiredService(p.ParameterType);
        }
    }
    return args;
}

This would also help resolve the cognitive complexity warnings on both methods.