Caching API responses

[mrueg]

As https://v6.vbb.transport.rest/ mentions, they support caching.

Caching-friendly[🔗](https://v6.vbb.transport.rest/#caching-friendly)

This API sends [ETag](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag) & [Cache-Control](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control) headers, allowing clients cache responses properly.

@vas3k do you know if this is something the custom component would benefit from? (I'm not sure if they reload every time the frontend card is triggered)

Also asking because there's a rate limit of 100 reqs/min