Use separate functions per format when parsing LC data from REST.
This allows to process events from the eventstream more directly,
as they are always JSON not SSZ. And also makes the code cleaner.
* allow trusted node sync based on LC trusted block root
Extends `trustedNodeSync` with a new `--trusted-block-root` option that
allows initializing a light client. No `--state-id` must be provided.
The beacon node will then use this light client to obtain the latest
finalized state from the remote server in a trust-minimized fashion.
Note that the provided `--trusted-block-root` should be somewhat recent,
and that security precautions such as comparing the state root against
block explorers is still recommended.
* fix
* workaround for `valueOr` limitations
* reduce magic numbers
* digest len > context len for readability
* move `cstring` conversion to caller
* avoid abbreviations
* `return` codestyle