* Update config for Ledger and CoreDb
why:
Prepare for tracer which depends on the API jump table (as well as
the profiler.) The API jump table is now enabled in unit/integration
test mode piggybacking on the `unittest2DisableParamFiltering`
compiler flag or on an extra compiler flag `dbjapi_enabled`.
* No deed for error field in `NodeRef`
why:
Was opnly needed by proof nodes pre-loader which will be re-implemented
* Cosmetics
* Updates and corrections
* Extract `CoreDb` configuration from `base.nim` into separate module
why:
This makes it easier to avoid circular imports, in particular
when the capture journal (aka tracer) is revived.
* Extract `Ledger` configuration from `base.nim` into separate module
why:
This makes it easier to avoid circular imports (if any.)
also:
Move `accounts_ledger.nim` file to sub-folder `backend`. That way the
layout resembles that of the `core_db`.