Default block fetch configuration parameters

Currently the default block fetch parameters are set in
[ouroboros-consensus](https://github.com/input-output-hk/ouroboros-network/blob/master/ouroboros-consensus/src/Ouroboros/Consensus/Node.hs?plain=1#L620)
but they belong to `cardano-node`. The `NodeConfiguration` should handle this
for us.

Start with the default block fetch parameters in ouroboros-consensus/src/Ouroboros/Consensus/Node.hs, around the location linked in the issue, and inspect how NodeConfiguration is defined and used. Trace the corresponding cardano-node configuration path. Done means the defaults are handled by NodeConfiguration rather than ouroboros-consensus, with affected tests or configuration checks passing.

Written by the indexing model from the issue text.