Add support for specifying non-clustered index sort direction

Author: gumbarros

src/Serilog.Sinks.MSSqlServer/Sinks/MSSqlServer/Platform/SqlCreateTableWriter.cs

@@ -54,7 +54,7 @@ public string GetSql()
 
                     // collect non-PK indexes for separate output after the table DDL
                     if (common != null && common.NonClusteredIndex && common != _columnOptions.PrimaryKey)
-                        ix.AppendLine(Invariant($"CREATE NONCLUSTERED INDEX [IX{indexCount++}_{_tableName}] ON [{_schemaName}].[{_tableName}] ([{common.ColumnName}]);"));
+                        ix.AppendLine(Invariant($"CREATE NONCLUSTERED INDEX [IX{indexCount++}_{_tableName}] ON [{_schemaName}].[{_tableName}] ([{common.ColumnName}] {common.NonClusteredIndexDirection});"));
                 }
             }
 

src/Serilog.Sinks.MSSqlServer/Sinks/MSSqlServer/SqlColumn.cs

@@ -100,6 +100,12 @@ public SqlDbType DataType
         /// </summary>
         public bool NonClusteredIndex { get; set; }
 
+        /// <summary>
+        /// Specifies the sort direction for a non-clustered index on the SQL column.
+        /// The default value is <see cref="SqlIndexDirection.Asc"/>. This property is only used when auto-creating a log table.
+        /// </summary>
+        public SqlIndexDirection NonClusteredIndexDirection { get; set; }
+
         /// <summary>
         /// The name of the Serilog property to use as the value when filling the DataTable.
         /// If not specified, the ColumnName and PropertyName are the same.

src/Serilog.Sinks.MSSqlServer/Sinks/MSSqlServer/SqlIndexDirection.cs

@@ -0,0 +1,18 @@
+namespace Serilog.Sinks.MSSqlServer
+{
+    /// <summary>
+    /// Defines the sort order for an SQL index.
+    /// </summary>
+    public enum SqlIndexDirection
+    {
+        /// <summary>
+        /// Represents the ascending direction for SQL indexing.
+        /// </summary>
+        Asc,
+
+        /// <summary>
+        /// Represents the descending direction for SQL indexing.
+        /// </summary>
+        Desc
+    }
+}