Small tweaks in parameter passing in simulated dm

(only had to modify generation of groundtruths)
changed initial starting states of robots in dm
added some basic path plotting code to test_simulation

Added a data-generator class to
generate data for simulated_dataset-manager

- internal robot_ctr that resets correctly
Order is (assuming 2 robots):
1: odo, meas
2: odo, meas
1: odo, meas
...

used when no measurement available for a given time

simulation now supports multiple landmarks
added handling for no measurement data
available at a given time (sim not over)

-working on incorporating multiple landmarks
-working on incorporating multiple robots
-working on handling of end of simulation vs. no meas. data available

Added custom noises to simulated_dataset_manager.py
Thorough review of simulated_dataset_manager reveals that it works correctly!
fixed delta_t with regards to alternation between measurement and odometry updates -> scheduling of this will change in next commit
will add multiple robots

Refactored some more elements of the code to be interchangable. Currently debugging communications of request/response messages.

1st iteration, next step is to add dynamic generation.

Add graph and gifs to README

See merge request !1