Feat: React children components support

[Lancetnik]

Hello there! I am a core developer of FastStream - the Python frameworks to build well-structured publish/consumes services for various Message Brokers. One of the great FastStream features users love - automatic AsyncAPI schema generation (and hosting) right from the service code. Thus, I have a little request to you.

For now, FastStream uses CDN React Component version to draw a static HTML represention of user service schema. But we can easely (cuz we have backend to serve this static site) implement test message publishing funtional right from a web schema (like OpenAPI allows you to send test HTTP requests). At first, test messages will be addressed only to the original FastStream service... But then we'll implement AsyncAPI schema -> FastStream service generation, that allows us to generate publishers "on flyight" and publish any message to any FastStream-supported Message Broker right from the website.

A slightly confusing preface... We need to ability pass some React-children components to the AsyncAPI react component to draw user payload input somewhere around payload example. We can create the component fork and implement our own component version (with all required inputs), but it is a bad way to build long-living tools. So, I hope on your team collaboration in this question and believe, that together we able to make AsyncAPI environment riacher.