Added support for inlining header refefences

Author: darrelmiller

src/Microsoft.OpenApi/Models/OpenApiHeader.cs

@@ -96,7 +96,7 @@ public void SerializeAsV3(IOpenApiWriter writer)
                 throw Error.ArgumentNull(nameof(writer));
             }
 
-            if (Reference != null)
+            if (Reference != null && writer.GetSettings().ReferenceInline != ReferenceInlineSetting.InlineLocalReferences)
             {
                 Reference.SerializeAsV3(writer);
                 return;
@@ -161,7 +161,7 @@ public void SerializeAsV2(IOpenApiWriter writer)
                 throw Error.ArgumentNull(nameof(writer));
             }
 
-            if (Reference != null)
+            if (Reference != null && writer.GetSettings().ReferenceInline != ReferenceInlineSetting.InlineLocalReferences)
             {
                 Reference.SerializeAsV2(writer);
                 return;

src/Microsoft.OpenApi/Writers/OpenApiWriterBase.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.IO;
 using Microsoft.OpenApi.Exceptions;
+using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.Properties;
 
 namespace Microsoft.OpenApi.Writers
@@ -14,6 +15,7 @@ namespace Microsoft.OpenApi.Writers
     /// </summary>
     public abstract class OpenApiWriterBase : IOpenApiWriter
     {
+        
         /// <summary>
         /// Settings for controlling how the OpenAPI document will be written out.
         /// </summary>