feat: Support nullable fields in TypeScript (box/box-codegen#612)

.codegen.json

@@ -1 +1 @@
-{ "engineHash": "a723fb8", "specHash": "6d5f53e", "version": "1.4.0" }
+{ "engineHash": "f6ccea9", "specHash": "6d5f53e", "version": "1.4.0" }

Box.Sdk.Gen.Tests.Integration/Test/Files/FilesManagerTests.cs

@@ -47,7 +47,7 @@ public async System.Threading.Tasks.Task TestCreateGetAndDeleteFile() {
             System.IO.Stream updatedContentStream = Utils.GenerateByteStream(size: 1024 * 1024);
             FileFull uploadedFile = await UploadFileAsync(fileName: newFileName, fileStream: updatedContentStream);
             FileFull file = await client.Files.GetFileByIdAsync(fileId: uploadedFile.Id);
-            await Assert.That.IsExceptionAsync(async() => await client.Files.GetFileByIdAsync(fileId: uploadedFile.Id, queryParams: new GetFileByIdQueryParams() { Fields = Array.AsReadOnly(new [] {"name"}) }, headers: new GetFileByIdHeaders(extraHeaders: new Dictionary<string, string>() { { "if-none-match", file.Etag } })));
+            await Assert.That.IsExceptionAsync(async() => await client.Files.GetFileByIdAsync(fileId: uploadedFile.Id, queryParams: new GetFileByIdQueryParams() { Fields = Array.AsReadOnly(new [] {"name"}) }, headers: new GetFileByIdHeaders(extraHeaders: new Dictionary<string, string>() { { "if-none-match", NullableUtils.Unwrap(file.Etag) } })));
             Assert.IsTrue(file.Name == newFileName);
             await client.Files.DeleteFileByIdAsync(fileId: uploadedFile.Id);
             TrashFile trashedFile = await client.TrashedFiles.GetTrashedFileByIdAsync(fileId: uploadedFile.Id);