Adds bindings for new GetState method in the state providers.

[francocipollone]

Related to maliput/maliput#458
Depends on maliput/maliput#473

Summary

As the title says, it adds bindings for the new GetState methods that are part of :

• maliput::api::rules::DiscreteValueRuleStateProvider
• maliput::api::rules::RangeValueRuleStateProvider

So it can be used like:

road_position = maliput.api.RoadPosition(lane, maliput.api.LanePosition(0., 0., 0.))
rule_type = maliput.api.rules.Rule.TypeId("Direction-Usage Rule Type");
state_result = road_network.discrete_value_rule_state_provider().GetState(road_position, rule_type, 1e-3)
print(state_result.state.value)

road_position = maliput.api.RoadPosition(lane, maliput.api.LanePosition(0., 0., 0.))
rule_type = maliput.api.rules.Rule.TypeId("Speed-Limit Rule Type");
state_result = road_network.range_value_rule_state_provider().GetState(road_position, rule_type, 1e-3)
print(state_result.state.max)

[agalbachicar]

LGTM