OpenAPI schema generation includes `status_code` but default exception handler never outputs that attribute
I was doing some endpoint schema validation for my project and ran into what seems like an inconsistency between the generated OpenAPI schema and reality.

Specifically, `HTTPException` has an (optional) `status_code` attribute which is typically set to the response status code when something exceptional happens.
The fact that this field should always be present in the output is documented in the generated schema, but in the code it is omitted in all cases in the default exception handler:
```py
if isinstance(exc, HTTPException):
    content = {"detail": exc.detail, "extra": exc.extra}
```

This currently makes my tests fail because the schema says status_code is required, but starlite will never output it.

There are two possible fixes for this:
1. Fix the OpenAPI schema generator not to include the field as required (or at all)
2. Update the default exception handler to include the field when it exists
diff --git a/starlite/app.py b/starlite/app.py
index 44080aa53..0c298b14c 100644
--- a/starlite/app.py
+++ b/starlite/app.py
@@ -283,7 +283,7 @@ class Starlite(Router):
             server_middleware = ServerErrorMiddleware(app=self)
             return server_middleware.debug_response(request=request, exc=exc)
         if isinstance(exc, HTTPException):
-            content = {"detail": exc.detail, "extra": exc.extra}
+            content = {"detail": exc.detail, "extra": exc.extra, "status_code": exc.status_code}
         elif isinstance(exc, StarletteHTTPException):
             content = {"detail": exc.detail}
         else:
diff --git a/starlite/openapi/responses.py b/starlite/openapi/responses.py
index d3ce2f6de..f196f08dd 100644
--- a/starlite/openapi/responses.py
+++ b/starlite/openapi/responses.py
@@ -125,7 +125,9 @@ def create_error_responses(exceptions: List[Type[HTTPException]]) -> Iterator[Tu
                 properties=dict(
                     status_code=Schema(type=OpenAPIType.INTEGER),
                     detail=Schema(type=OpenAPIType.STRING),
-                    extra=Schema(type=OpenAPIType.OBJECT, additionalProperties=Schema()),
+                    extra=Schema(
+                        type=[OpenAPIType.NULL, OpenAPIType.OBJECT, OpenAPIType.ARRAY], additionalProperties=Schema()
+                    ),
                 ),
                 description=pascal_case_to_text(get_name(exc)),
                 examples=[{"status_code": status_code, "detail": HTTPStatus(status_code).phrase, "extra": {}}],
diff --git a/tests/app/test_error_handling.py b/tests/app/test_error_handling.py
index 009277596..d7a5899a3 100644
--- a/tests/app/test_error_handling.py
+++ b/tests/app/test_error_handling.py
@@ -27,6 +27,40 @@ def test_default_handle_http_exception_handling() -> None:
     assert json.loads(response.body) == {
         "detail": "starlite_exception",
         "extra": {"key": "value"},
+        "status_code": 500,
+    }
+
+    response = Starlite(route_handlers=[]).default_http_exception_handler(
+        Request(scope={"type": "http", "method": "GET"}),
+        HTTPException(detail="starlite_exception"),
+    )
+    assert response.status_code == HTTP_500_INTERNAL_SERVER_ERROR
+    assert json.loads(response.body) == {
+        "detail": "starlite_exception",
+        "extra": None,
+        "status_code": 500,
+    }
+
+    response = Starlite(route_handlers=[]).default_http_exception_handler(
+        Request(scope={"type": "http", "method": "GET"}),
+        HTTPException(detail="starlite_exception", extra=None),
+    )
+    assert response.status_code == HTTP_500_INTERNAL_SERVER_ERROR
+    assert json.loads(response.body) == {
+        "detail": "starlite_exception",
+        "extra": None,
+        "status_code": 500,
+    }
+
+    response = Starlite(route_handlers=[]).default_http_exception_handler(
+        Request(scope={"type": "http", "method": "GET"}),
+        HTTPException(detail="starlite_exception", extra=["extra-1", "extra-2"]),
+    )
+    assert response.status_code == HTTP_500_INTERNAL_SERVER_ERROR
+    assert json.loads(response.body) == {
+        "detail": "starlite_exception",
+        "extra": ["extra-1", "extra-2"],
+        "status_code": 500,
     }
 
     response = Starlite(route_handlers=[]).default_http_exception_handler(
diff --git a/tests/test_template.py b/tests/test_template.py
index e3391e9b2..1661a7076 100644
--- a/tests/test_template.py
+++ b/tests/test_template.py
@@ -52,7 +52,7 @@ def test_jinja_raise_for_invalid_path(tmpdir: Any) -> None:
     ) as client:
         response = client.request("GET", "/")
         assert response.status_code == 500
-        assert response.json() == {"detail": "Template invalid.html not found.", "extra": None}
+        assert response.json() == {"detail": "Template invalid.html not found.", "extra": None, "status_code": 500}
 
 
 def test_mako_template(tmpdir: Any) -> None:
@@ -101,7 +101,7 @@ def test_mako_raise_for_invalid_path(tmpdir: Any) -> None:
     ) as client:
         response = client.request("GET", "/")
         assert response.status_code == 500
-        assert response.json() == {"detail": "Template invalid.html not found.", "extra": None}
+        assert response.json() == {"detail": "Template invalid.html not found.", "extra": None, "status_code": 500}
 
 
 def test_handler_raise_for_no_template_engine() -> None:
@@ -112,7 +112,7 @@ def test_handler_raise_for_no_template_engine() -> None:
     with create_test_client(route_handlers=[invalid_path]) as client:
         response = client.request("GET", "/")
         assert response.status_code == 500
-        assert response.json() == {"detail": "Template engine is not configured", "extra": None}
+        assert response.json() == {"detail": "Template engine is not configured", "extra": None, "status_code": 500}
 
 
 def test_template_with_no_context(tmpdir: Any) -> None:
['tests/test_template.py', 'starlite/openapi/responses.py', 'tests/app/test_error_handling.py', 'starlite/app.py']