Supports loading rules via RuleRegistry + new RoadRulebook format.

[francocipollone]

Part of #193

Summary

• Support "new" rules loading:
  • Load RuleRegistry from file
  • Load RuleBook from file based on new rules that rely on the RuleRegistry.
• Adds the new-rule version of figure8_trafficlights.yaml description:
  • Adds RuleRegistry section
  • Modifies RoadRulebook section to the new rule format.

Pendings

• [x] Add tests for RuleRegistry builder
• [ ] Add tests for RoadRulebook builder

[francocipollone]

Based on our F2F I split the RoadRulebookBuilder into two different functors:

• RoadRulebookBuilderOldRules: For usign old rule api. Old rules are loaded from RoadRulebook yaml file(old format). Also new rules are populated from here.
• RoadRulebookBuidler : For using new rule api. Only new rules are loaded.

@agalbachicar Regarding RoadRulebookBuilderOldRules I have my doubts about continuing to populate the new rules in this case. I think that now that we fully support both apis there is no need to have "partially" loaded the new rules when we only care about old rules. It would be simpler if we just : 1 - Care only about old rules when no rule registry is passed and the old format rule is being used. 2 - Care only about new rules when rule registry is passed and the new format rule is being used.

I will continue working now on the test for the RoadRulebook builders.