Use `truncateBytes` to log `blockRoot`

I'd like `blockRoot` to be fully printed consistently so that it's easier to debug
you search for it through explorer then copy it to our loki explorer. If it's not consistent then it make it harder to debug. Does anybody agree?

this is different to peerId where we print it fully 1 time and pretty print in all other times

_Originally posted by @twoeths in https://github.com/ChainSafe/lodestar/pull/8390#pullrequestreview-3222743320_

Search the logging paths that emit blockRoot and inspect how truncateBytes is used for related identifiers. Compare the intended output with the existing peerId logging behavior, then verify that blockRoot is printed fully and consistently in Loki-oriented logs.

Written by the indexing model from the issue text.