Take version into account in nodeBlockFetchSize

Currently, `nodeBlockFetchSize` does not take the `BlockNodeToNodeVersion` (it's not used for `NodeToClient` protocols at the moment) into account when coming up with an estimate for the block size. This means that if for a certain version, the blocks are larger, `nodeBlockFetchSize` would have to overestimate for the other versions, just to make sure that it never underestimates.

Note that eventually `nodeBlockFetchSize` should be removed from `RunNode`.

Locate nodeBlockFetchSize and its RunNode call sites, then inspect how BlockNodeToNodeVersion is represented and used in the block-fetch sizing path. Done means the estimate accounts for the relevant version without underestimating larger blocks, while keeping in mind the eventual removal of nodeBlockFetchSize from RunNode.

Vom Indexierungsmodell aus dem Issue-Text verfasst.