Renames joint dynamic and static friction variables

[matthewtrepte]

Description

Rename misnamed joint coefficient variables in Articulation as the new joint friction APIs are forces/torques and not coefficients.

In Articulation

• Rename joint_friction_coeff to joint_static_friction_effort
• Rename joint_dynamic_friction_coeff to joint_dynamic_friction_effort
• Update a few comments / descriptions
• Added proxies to preserve old name and mark them as deprecated

Type of change

• Bug fix (non-breaking change which fixes an issue)

Screenshots

Please attach before and after screenshots of the change if applicable.

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there

[jtigue-bdai]

all looks good. the main thing is the use of torque. In most cases it will be torque but for prismatic joints it will be a force. Effort is a more general term but you can add clarification that effort (force or torque).

[kellyguo11]

maybe we can mark this as deprecated as well and keep it for now for backward support for 4.5 where it's still a coefficient. we can update the docstring to mention in 4.5 it's coeff, and in 5.0+ it's effort. then, we can also create a new static_friction parameter for the new API that will be effort. @jtigue-bdai do you think that would make sense?

[matthewtrepte]

done, though please check again

[Mayankm96]

Let's merge this after #3318 is done since that one has been hanging for a while.