Investigate extracting so101 and widowx as dedicated plugins

[MarkRedeman]

In studio we need to manually define the RobotCatalogDefinition for SO101 and WidowX arms.

• SO101.py
• widowxai.py

We also perform some extra logic to sync robot assets this makes it so that Studio can download the STL and URDF files of those robots.

I'd like to look into moving the plugin definitions into the physicalai repo. This would also allow us to host the urdf + stl files here, and have a dedicated leader models for so101 and widowx. See so101_leader.urdf from my kiwi plugin for a leader so101.