Remove V2 Loggers

[jwaa]

Is your feature request related to a problem? Please describe.
The V2 loggers (e.g., GridWorldLoggerV2) need to be removed. After being deprecated according to #289

This also includes the removal of these lines in GridWorld.__step, as the check is then no longer needed:

# Check if the logger is an old or V2 version.
if isinstance(logger, GridWorldLoggerV2):
    logger._grid_world_log(world_state=world_state, agent_data=agent_data_dict, grid_world=self,
                           last_tick=self.__is_done, goal_status=goal_status)
else:
    logger._grid_world_log(agent_data=agent_data_dict, grid_world=self,
                           last_tick=self.__is_done, goal_status=goal_status)

Describe the solution you would like
N/A

Describe alternatives you have considered
N/A

Additional context
The last step after #289 to allow for sufficient time to go for MATRX users to adapt to the V2 loggers and then to phase out the V2 back to normal naming.