Support "catch all" http trigger route

Writing a route like `{*path}` and `{**path}` to get all subsequent path parameters did not correctly output the OpenAPI definition.

`Microsoft.Azure.WebJobs.Extensions.OpenApi`: `0.5.1-preview`

### Repro code

```csharp
[FunctionName("CatchAll")]
[OpenApiOperation(operationId: "CatchAll", tags: new[] { "name" })]
[OpenApiParameter("path", In = ParameterLocation.Path, Type = typeof(string))]
[OpenApiResponseWithoutBody(HttpStatusCode.OK)]
public static ActionResult CatchAll([HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "catchall/{*path}")]
HttpRequest req,
string path)
{
return new OkObjectResult(path);
}
```

### Actual behavior