Update Swashbuckle and improve generated OpenAPI files (#6066)

* Improve generated OpenAPI files

* Nullable

* Fmt

* Correct powershell command

* Fix name

* Add some tests

* Fmt

* Switch to using json naming policy

test/SharedWeb.Test/GitCommitDocumentFilterTest.cs

@@ -0,0 +1,23 @@
+using Bit.SharedWeb.Swagger;
+using Microsoft.OpenApi.Models;
+using Swashbuckle.AspNetCore.SwaggerGen;
+
+namespace SharedWeb.Test;
+
+public class GitCommitDocumentFilterTest
+{
+    [Fact]
+    public void AddsGitCommitExtensionIfAvailable()
+    {
+        var doc = new OpenApiDocument();
+        var context = new DocumentFilterContext(null, null, null);
+        var filter = new GitCommitDocumentFilter();
+        filter.Apply(doc, context);
+
+        Assert.True(doc.Extensions.ContainsKey("x-git-commit"));
+        var ext = doc.Extensions["x-git-commit"] as Microsoft.OpenApi.Any.OpenApiString;
+        Assert.NotNull(ext);
+        Assert.False(string.IsNullOrEmpty(ext.Value));
+
+    }
+}