Make TurboStream a Marten::HTTP::Response

[treagod]

Description

In order to directly use a Turbo Stream as response instead using it in #respond it could be interesting to have MartenTurbo::TurboStream as as Marten::HTTP::Response.

Example:

class ArticleHandler < Marten::Handlers::Schema
  schema ArticleHandler
  template_name "article_form.html"
  success_route_name "articles"

  after_successful_schema_validation :turbo

  private def turbo : Nil
    return turbo_stream if request.turbo?
  end

  private def turbo_stream
    # Creating it here for demonstrating purpose
    article = Article.new(schema.validated_data)
    article.save!

    MartenTurbo::TurboStream.new do |stream|
      stream.append("articles", "<div>Article #{article.pk}</div>")
    end
  end
end