It was impossible to package further versions before
because listmonk upstream was using a very EOL Go version.

I was waiting for upstream to bump this, but it didn't happen, so I take
the matters in my hand.

Hopefully, the upstream PR will be accepted.

Previously, the transactional template was in id=2.
It is now id=3.

I moved a bit the code to improve the ability to load templates and subscribers properly.
I am planning to upstream `type` for templates API request so we can easily filter out
and select the accordingly template.

Otherwise, Darwin will try to run them and fail.