[FEATURE]: Refactor angler_mux interface to improve usability

[evan-palmer]

Feature Type

Changing existing functionality in Angler

Problem Description

Angler currently uses the angler_mux interface to "demux" system commands and send them to the respective subsystems (the system's manipulators and base). The angler_mux interface is also used to "mux" the full-system state. Ultimately, this interface is convoluted and will be challenging to maintain in the future as additional models are added and functionality is developed out.

Feature Description

While the current "mux" is fine, the "demux" design should be either redone or removed altogether in favor of of a better interface. If there are alternative designs which can be applied to remove both of these interfaces, then that approach should be preferred. Some ideas regarding how to remove the "demux" interface are as follows:

• Integrate a ros2_control interface with support to send joint trajectory commands to the full system
• Redesign the demux to be less rigid and better improve abstractions and interfaces
• Eliminate the interface altogether and send commands directly to each system from the motion planner

I would ultimately like to see an interface come together in a way similar to the PR2 or Fetch

Alternative Solutions

NO ALTERNATIVES - GET RID OF IT

Additional Context

No response

[evan-palmer]

I wonder if one way to approach this could be to split this up by model? Each different model could have it's own mux/demux. Although this may make things too complex. I like the current approach to the mux (integration of message_filters), but I still have quite a bit of animosity toward the demux at the moment.