refactor: Only make bloc factories internal

[provokateurin]

Closes #1372

For the neon_* packages this has not effect since they still have the global ignore set (which we should change eventually).

[Leptopoda]

It's not that hard to write propper documentation here and we should do so moving forward.

[provokateurin]

I agree and I plan to do that, but for now I only want to change this to enable it. I'll create another issue to document all the blocs.

[provokateurin]

As the commit says this is only a refactor to enabled easier detection of missing docs. I do not want to add the docs in this PR already.

[Leptopoda]

I still disagree.
It's not a big deal to add a few lines of docs. I fear that any open issue will just rot (similar to #1119)