Deserialize and build overall configuration from config sources
Unrecognized config keys are reported as log warning messages.
Resolve the whole configuration in one go, using the
Resolvable impl on
if necessary, so that unrecognized config key processing works correctly.
This performs step 3 of the overall config processing,
as described in the
tor_config crate-level documentation.
For an example, see the
tor_config::load module-level documentation.