add features to TikzGenerator

* Add config to choose if all or only alive trajectories are drawn
* Draw walking direction in Tikz
* create nodes for pedestrian instead of circles. Each pedestrian node
  has a name 'ped_ID' to reference the node in tikz.
* add named coordinate at Centroid for all scenario elements:
  * source: (src_<ID>)
  * target: (trg_<ID>)
  * absorbingArea: (absorb_<ID>)
  * obstacle: (obs_<ID>)
  * stairs: (str_<ID>)
  * measurementArea: (mrmtA_<ID>)
* add style classes:
  * trajectory: i.e. thickness
  * pedestrian: default color
  * ped_circle: defines shape of circular pedestrians (not for groups)
  * selected: style for selected pedestrian
  * group: styl (all) groups.
8 jobs for tikzgenerator-feature in 133 minutes and 37 seconds