Improvements on pipeline architecture v2

[raulb]

As part of releasing Conduit v0.12.2, we wanted to bring https://github.com/ConduitIO/conduit/pull/1913, but there were some comments posted by @hariso that remained un addressed.

Here are the ones I identified from that pull-request. @hariso to confirm:

• [ ] https://github.com/ConduitIO/conduit/pull/1913#discussion_r1806624491
• [ ] https://github.com/ConduitIO/conduit/pull/1913#discussion_r1806782612
• [ ] https://github.com/ConduitIO/conduit/pull/1913#discussion_r1808575111
• [ ] https://github.com/ConduitIO/conduit/pull/1913#discussion_r1821279315

[hariso]

Yup, those are the comments that we still want to discuss!