Use the Options pattern for configuring IOpenApiConfigurationOptions

Would it be possible to register IOpenApiConfigurationOptions as an instance of IOptions so it can be configured liked this:

```csharp
builder.Services.Configure(options =>
{
options.Info.Title = "My API";
});
```

You should also be able to configure it using the existing [configuration providers](https://docs.microsoft.com/en-us/dotnet/core/extensions/configuration-providers).

I think this is more typical for configuring options in ASP.NET than the environment variable or inheritance approaches that are currently supported.

Start by locating where IOpenApiConfigurationOptions is registered and how the existing environment-variable or inheritance approaches configure it. Compare that path with the linked .NET configuration providers and the Configure example; done means both configuration styles can supply the options.

Written by the indexing model from the issue text.