Duplicate components of `endeff_6D` observation

[Mcibula]

Hello!

I am working with the latest version of master branch.

When I use endeff_6D as an additional observation, I get a 11D vector for that observation part instead of the usual 7D. The problem seems to be that the 4D effector orientation is there twice.

The duplicity is probably caused by the code generating the observation in TaskModule.get_additional_obs() method that concatenates outputs of VisionModule.get_obj_position() and VisionModule.get_obj_rotation(); however, the output of the former already contains orientation.

Thank you.