Multiple Chain Calls in parallel

[chr-hertel]

Already running in a situation where I'd like to have the capabilities to execute multiple calls to the chain in parallel since it consumes a significant time extra to run it sequentially right now.

Maybe simple as the HTTP Client does it
https://symfony.com/doc/current/http_client.html#concurrent-requests

[chr-hertel]

With #141 at least parallel platform calls are possible