Fixing all the TODO, FIXME & HACK comments so they all follow the same layout.

src/Umbraco.Web/PublishedCache/NuCache/DataSource/BTree.DictionaryOfCultureVariationSerializer.cs

@@ -36,7 +36,7 @@ namespace Umbraco.Web.PublishedCache.NuCache.DataSource
             // write each variation
             foreach (var (culture, variation) in variations)
             {
-                // todo - it's weird we're dealing with cultures here, and languageId in properties
+                // TODO: it's weird we're dealing with cultures here, and languageId in properties
 
                 PrimitiveSerializer.String.WriteTo(culture, stream); // should never be null
                 WriteObject(variation.Name, stream); // write an object in case it's null (though... should not happen)

src/Umbraco.Web/PublishedCache/NuCache/DataSource/DatabaseDataSource.cs

@@ -15,7 +15,7 @@ using static Umbraco.Core.Persistence.NPocoSqlExtensions.Statics;
 
 namespace Umbraco.Web.PublishedCache.NuCache.DataSource
 {
-    // todo - use SqlTemplate for these queries else it's going to be horribly slow!
+    // TODO: use SqlTemplate for these queries else it's going to be horribly slow!
 
     // provides efficient database access for NuCache
     internal class DatabaseDataSource : IDataSource

src/Umbraco.Web/PublishedCache/NuCache/DataSource/PropertyData.cs

@@ -12,14 +12,14 @@ namespace Umbraco.Web.PublishedCache.NuCache.DataSource
         public string Culture
         {
             get => _culture;
-            set => _culture = value ?? throw new ArgumentNullException(nameof(value)); // todo or fallback to string.Empty? CANNOT be null
+            set => _culture = value ?? throw new ArgumentNullException(nameof(value)); // TODO: or fallback to string.Empty? CANNOT be null
         }
 
         [JsonProperty("seg")]
         public string Segment
         {
             get => _segment;
-            set => _segment = value ?? throw new ArgumentNullException(nameof(value)); // todo or fallback to string.Empty? CANNOT be null
+            set => _segment = value ?? throw new ArgumentNullException(nameof(value)); // TODO: or fallback to string.Empty? CANNOT be null
         }
 
         [JsonProperty("val")]