Refactor TSP construction

[jcoupey]

To define a tsp, we're currently passing a vector of indices that relates to rows and columns in input::_matrix. Doing so does not keep track of the respective positions of jobs and vehicle start/end, hence the recent addition of input::_type_with_ids storing that information along with locations. This approach is overly complicated and will break when merging #75 anyway.

Instead it would be much simpler to describe the jobs passed to the tsp ctor from their ranks in input::_jobs.

[jcoupey]

Done in #89