DAL/Node: simpler bootstrap mode
What
Simplifies the bootstrap node, and makes it more clear what a bootstrap node does.
Why
Bootstrap nodes don't need to process slot headers, to accuse, etc. They just need to keep up to date with topics.
How
Just factor out the steps that a bootstrap node does not need to do.
Manually testing the MR
CI should suffice.
Edited by Eugen Zalinescu