Improved set of extension docker images

[dominikriemer]

Hi,
I created an issue at #2122 that describes how we can reduce the current set of docker images for extensions.

The goal is to reduce the number of various extension containers and to provide a more lightweight image for edge deployments.

What do you think? Which adapters and pipeline elements should be part of the minimal image and which are ones we can exclude?

I'll also provide a PR with an initial suggestion as a basis for the discussion.