Add PhotoUpload feature for uploading photos to file storage

Adds UploadPhotoCommand/Handler/Validator and PhotoUploadRepository, invoked via MediatR by other features' commands (e.g. a future CreateBreweryPhoto) rather than exposed through its own controller. Wires the feature and IFileStorageProvider into API.Core.

web/backend/Features/Features.PhotoUpload/DependencyInjection/FeaturesPhotoUploadServiceCollectionExtensions.cs

@@ -0,0 +1,16 @@
+using Features.ImageUploads.Repository;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Features.ImageUploads.DependencyInjection;
+
+/// <summary>Registers the services required by the PhotoUpload feature.</summary>
+public static class FeaturesPhotoUploadServiceCollectionExtensions
+{
+    /// <summary>Registers <see cref="IPhotoUploadRepository" /> and its implementation.</summary>
+    /// <returns><paramref name="services" />, for chaining.</returns>
+    public static IServiceCollection AddFeaturesPhotoUpload(this IServiceCollection services)
+    {
+        services.AddScoped<IPhotoUploadRepository, PhotoUploadRepository>();
+        return services;
+    }
+}