Consider returning reference type from `AddComponent` API

The AddComponent API currently returns a boolean that indicates if the addition of the component to the document registry succeeded.

It would be nice if the API returned a reference to the item that was just constructed. In an M.A.OpenAPI transformer, I currently need to write:

options.AddOperationTransformer((operation, context, cancellationToken) =>
{
    var schemaService = context.ApplicationServices.GetRequiredKeyedService<IOpenApiSchemaService>(context.DocumentName);
    if (context.Description.RelativePath == "error")
    {
        var errorSchema = schemaService.GetOrCreateSchema(typeof(ProblemDetails));
        context.Document.AddComponent("Error", errorSchema);
        operation.Responses["500"] = new OpenApiResponse
        {
            Description = "Error",
            Content =
            {
                ["application/problem+json"] = new OpenApiMediaType
                {
                    Schema = new OpenApiSchemaReference("Error", context.Document),
                },
            },
        };
    }
    return Task.CompletedTask;
});

but would like to write:

options.AddOperationTransformer((operation, context, cancellationToken) =>
{
    var schemaService = context.ApplicationServices.GetRequiredKeyedService<IOpenApiSchemaService>(context.DocumentName);
    if (context.Description.RelativePath == "error")
    {
        var errorSchema = schemaService.GetOrCreateSchema(typeof(ProblemDetails));
        var insertedSchema = context.Document.AddComponent("Error", errorSchema);
        operation.Responses["500"] = new OpenApiResponse
        {
            Description = "Error",
            Content =
            {
                ["application/problem+json"] = new OpenApiMediaType
                {
                    Schema = insertedSchema,
                },
            },
        };
    }
    return Task.CompletedTask;
});

cc: @baywet I couldn't see if an API that did this existed already and figured I'd add the proposal.

Inizia individuando l’implementazione dell’API AddComponent e qualsiasi copertura esistente per la registrazione dei componenti del documento. Confronta il suo risultato booleano attuale con l’esempio di AddOperationTransformer, quindi verifica che il riferimento restituito rappresenti lo schema inserito mentre il comportamento di registrazione esistente rimane intatto.