Moved configuration setting POCOs into Umbraco.Core and adjusted references.

Amended injection of some settings to use IOptionsSnapshot.

src/Umbraco.Core/Configuration/ContentSettingsExtensions.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Linq;
+using Umbraco.Core.Configuration.Models;
+using Umbraco.Core.Configuration.UmbracoSettings;
+
+namespace Umbraco.Core.Configuration
+{
+    public static class ContentSettingsExtensions
+    {
+        /// <summary>
+        /// Gets a value indicating whether the file extension corresponds to an image.
+        /// </summary>
+        /// <param name="extension">The file extension.</param>
+        /// <param name="contentConfig"></param>
+        /// <returns>A value indicating whether the file extension corresponds to an image.</returns>
+        public static bool IsImageFile(this ContentSettings contentConfig, string extension)
+        {
+            if (contentConfig == null) throw new ArgumentNullException(nameof(contentConfig));
+            if (extension == null) return false;
+            extension = extension.TrimStart('.');
+            return contentConfig.Imaging.ImageFileTypes.InvariantContains(extension);
+        }
+
+        /// <summary>
+        /// Determines if file extension is allowed for upload based on (optional) white list and black list
+        /// held in settings.
+        /// Allow upload if extension is whitelisted OR if there is no whitelist and extension is NOT blacklisted.
+        /// </summary>
+        public static bool IsFileAllowedForUpload(this ContentSettings contentSettings, string extension)
+        {
+            return contentSettings.AllowedUploadFiles.Any(x => x.InvariantEquals(extension)) ||
+                (contentSettings.AllowedUploadFiles.Any() == false &&
+                contentSettings.DisallowedUploadFiles.Any(x => x.InvariantEquals(extension)) == false);
+        }
+
+        /// <summary>
+        /// Gets the auto-fill configuration for a specified property alias.
+        /// </summary>
+        /// <param name="contentSettings"></param>
+        /// <param name="propertyTypeAlias">The property type alias.</param>
+        /// <returns>The auto-fill configuration for the specified property alias, or null.</returns>
+        public static IImagingAutoFillUploadField GetConfig(this ContentSettings contentSettings, string propertyTypeAlias)
+        {
+            var autoFillConfigs = contentSettings.Imaging.ImageAutoFillProperties;
+            return autoFillConfigs?.FirstOrDefault(x => x.Alias == propertyTypeAlias);
+        }
+    }
+}