Return more detail when invalid data is found in the DB during startup (#2445)
Return more detail when invalid data is found in the DB during startup (#2445)

## Issue Addressed

- Resolves #2444

## Proposed Changes

Adds some more detail to the error message returned when the `BeaconChainBuilder` is unable to access or decode block/state objects during startup.

## Additional Info

NA




sigp/lighthouse,sigp/lighthouse,sigp/lighthouse,sigp/lighthouse