Enable nullable for more files and add tests

Adds basic tests for FFProbeVideoInfo.CreateDummyChapters
Fixed error message CreateDummyChapters instead of reporting the total minutes it only reported the minute component

MediaBrowser.Controller/Drawing/IImageProcessor.cs

@@ -66,7 +66,7 @@ namespace MediaBrowser.Controller.Drawing
         /// <returns>Guid.</returns>
         string GetImageCacheTag(BaseItem item, ItemImageInfo image);
 
-        string GetImageCacheTag(BaseItem item, ChapterInfo chapter);
+        string? GetImageCacheTag(BaseItem item, ChapterInfo chapter);
 
         string? GetImageCacheTag(User user);
 

MediaBrowser.Controller/Entities/ItemImageInfo.cs

@@ -1,5 +1,3 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
 using System;
@@ -14,7 +12,7 @@ namespace MediaBrowser.Controller.Entities
         /// Gets or sets the path.
         /// </summary>
         /// <value>The path.</value>
-        public string Path { get; set; }
+        public required string Path { get; set; }
 
         /// <summary>
         /// Gets or sets the type.
@@ -36,9 +34,9 @@ namespace MediaBrowser.Controller.Entities
         /// Gets or sets the blurhash.
         /// </summary>
         /// <value>The blurhash.</value>
-        public string BlurHash { get; set; }
+        public string? BlurHash { get; set; }
 
         [JsonIgnore]
-        public bool IsLocalFile => Path is null || !Path.StartsWith("http", StringComparison.OrdinalIgnoreCase);
+        public bool IsLocalFile => !Path.StartsWith("http", StringComparison.OrdinalIgnoreCase);
     }
 }

MediaBrowser.Controller/Security/IAuthenticationManager.cs

@@ -1,6 +1,4 @@
-#nullable enable
-
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace MediaBrowser.Controller.Security