Small refactoring to simplify 6.0 migration and adjust comments

Author: bahusoid

src/NHibernate/Criterion/EntityProjection.cs

@@ -81,6 +81,7 @@ public EntityProjection SetFetchLazyProperties(bool fetchLazyProperties = true)
 
 		/// <summary>
 		/// Fetch individual lazy properties or property groups
+		/// Provide lazy property name and it will be fetched along with properties that belong to the same fetch group (lazy-group)
 		/// Note: To fetch single property it must be mapped with unique fetch group (lazy-group)
 		/// </summary>
 		public EntityProjection SetFetchLazyPropertyGroups(params string[] lazyPropertyGroups)

src/NHibernate/Loader/OuterJoinableAssociation.cs

@@ -203,6 +203,7 @@ internal string GetSelectFragment(string entitySuffix, string collectionSuffix,
 			{
 				case SelectMode.Undefined:
 				case SelectMode.Fetch:
+					//TODO 6.0: Just drop obsolete parts making all 3 cases handled by the same code
 #pragma warning disable 618
 					return Joinable.SelectFragment(
 						next?.Joinable,
@@ -228,16 +229,17 @@ internal string GetSelectFragment(string entitySuffix, string collectionSuffix,
 
 				case SelectMode.FetchLazyPropertyGroup:
 					return ReflectHelper.CastOrThrow<ISupportLazyPropsJoinable>(Joinable, "fetch lazy property")
-					                    .SelectFragment(
-						                    next?.Joinable,
-						                    next?.RHSAlias,
-						                    RHSAlias,
-						                    collectionSuffix,
-						                    ShouldFetchCollectionPersister(),
-						                    new EntityLoadInfo(entitySuffix)
-						                    {
-							                    LazyProperties = EntityFetchLazyProperties
-						                    });
+										.SelectFragment(
+											next?.Joinable,
+											next?.RHSAlias,
+											RHSAlias,
+											collectionSuffix,
+											ShouldFetchCollectionPersister(),
+											new EntityLoadInfo(entitySuffix)
+											{
+												LazyProperties = EntityFetchLazyProperties, 
+												IncludeLazyProps = SelectMode == SelectMode.FetchLazyProperties,
+											});
 				case SelectMode.ChildFetch:
 					return ReflectHelper.CastOrThrow<ISupportSelectModeJoinable>(Joinable, "child fetch select mode")
 					                    .IdentifierSelectFragment(RHSAlias, entitySuffix);

src/NHibernate/SelectMode.cs

@@ -33,12 +33,13 @@ public enum SelectMode
 		JoinOnly,
 
 		/// <summary>
-		/// Skips fetching for eagerly mapped association (no-op for lazy association).
+		/// Skips fetching for fetch="join" association (no-op for lazy association).
 		/// </summary>
 		Skip,
 
 		/// <summary>
-		/// Fetch lazy property group
+		/// Fetch lazy property group.
+		/// Provide path to lazy property and it will be fetched along with properties that belong to the same fetch group (lazy-group)
 		/// Note: To fetch single property it must be mapped with unique fetch group (lazy-group)
 		/// </summary>
 		FetchLazyPropertyGroup,