V10/bugfix/14543 publish descendants

[Migaroez]

Reason

Fix for #14543

Description

• Renamed vars to clear up some things
• Skipped the branchitem change detection on the root node as the action implies we want to save and publish the root
• Seperated the root and children publish results to have seperate references to them later on
• Used the seperated root reference to properly check if the root was succesful after all the children are processed.
• Passed the state of root from the publishing to the published notification properly linking the pair together

Reproduction steps

Add the following classes to your project

using Umbraco.Cms.Core.Composing;
using Umbraco.Cms.Core.Events;
using Umbraco.Cms.Core.Notifications;

public class Published : INotificationAsyncHandler<ContentPublishedNotification>
{
    public Task HandleAsync(ContentPublishedNotification notification, CancellationToken cancellationToken)
    {
        notification.State.TryGetValue("publishing", out var value);

        return Task.CompletedTask;
    }
}
public class Publishing : INotificationAsyncHandler<ContentPublishingNotification>
{
    public Task HandleAsync(ContentPublishingNotification notification, CancellationToken cancellationToken)
    {
        notification.State.Add("publishing", notification.PublishedEntities.Select(x => x.Id).ToList());

        return Task.CompletedTask;
    }
}

public class Saved : INotificationAsyncHandler<ContentSavedNotification>
{
    public Task HandleAsync(ContentSavedNotification notification, CancellationToken cancellationToken)
    {
        notification.State.TryGetValue("saving", out var value);

        return Task.CompletedTask;
    }
}
public class Saving : INotificationAsyncHandler<ContentSavingNotification>
{
    public Task HandleAsync(ContentSavingNotification notification, CancellationToken cancellationToken)
    {
        notification.State.Add("saving", notification.SavedEntities.Select(x => x.Id).ToList());

        return Task.CompletedTask;
    }
}

public class MyComposer : IComposer
{
    public void Compose(IUmbracoBuilder builder)
    {
        builder.AddNotificationAsyncHandler<ContentPublishingNotification, Publishing>();
        builder.AddNotificationAsyncHandler<ContentPublishedNotification, Published>();
        builder.AddNotificationAsyncHandler<ContentSavingNotification, Saving>();
        builder.AddNotificationAsyncHandler<ContentSavedNotification, Saved>();
    }
}

Each pair (save or publish) should be hit for every child that has unpublished changes when executing publish with descendants on a parent (or ancestor for that matter).
These pairs should also be called on the parent
And the state should be passed between each item in a pair.

[Zeegaan]

Found a few small things 👀

[Zeegaan]

Looks good, tests good!