Sonataflow extension modularization

[fjtirado]

Description

Currently, sonataflow extension contains code for generation of async, openapi and grpc work item handlers.
Although this works fine, I think it will worthy to split it into several modules: one with asyncapi stuff, another with grpc stuff, another with openapistuff and keep the rest in the current one
For backward compatibility reasons, these new modules will still be included as dependencies of the existing extension, but, after this change, it will be possible (with a reasonable amount of effort) to deploy sonataflow with less dependencies for users that do not want grpc, async or openapi.

Implementation ideas

No response