Improve the "Objective" ranking value for "PlannedTrip" instances

[garciparedes]

Is your feature request related to a problem? Please describe.
This issue is related with #7 due to in this case the Objective is related with the minimization of the costs. But when you need to pick the next PlannedTask on the InsertionAlgorithm, the best choice is not always related with the lowest cost PlannedTask. This issue is also related with #12 because allowing the possibility of serving multiple Trips at the same time will produce a changes in the scoring strategies.

Describe the solution you'd like
A good solution for that kind of situations can be to define a scoring (or something like that) measurement that reflects the possible "quality" of a PlannedTrip, which will not necessarily be related to the optimization function.

Describe alternatives you've considered
The alternative is to use only the planned_trip_optimization(...) method, which restricts produces restrictions in the versatility of the Objective definition.

Additional context
A good point can be to have a default set of possible scoring strategies, that a user can use and even extend. Maybe this strategies can depend on the Route state.