Feature request: Environment representation as single source of information

[alexander-sung]

We should design and implement an environment representation which completely describes the world state, especially for use by the planner. It should contain both static and dynamic information, and all other components should provide their information to the interfaces of this module, or query from its interfaces, respectively.

Motivation for this request comes from the intent to get rid of the create-on-demand functionality of objects (https://github.com/DFKI-NI/mobipick_labs/blob/noetic/tables_demo_planning/src/tables_demo_planning/components.py#L20), which outlived its usefullness and by now causes us more problems than it is helpful. Currently, we can't simply delete it as code would break, and it wouldn't make sense to define object creation somewhere in the executables since this as well caused us problems in the past and is prone to errors in the future.

For your information, @sebastianstock, @marcvinci, @mintar.