Fix reset functions

[johnBuffer]

Description

This PR introduces a reset_joints_to_default function that reset all joints of a robot to their default states.
It also introduces the possibility to target specific joints in the reset_joints_by_scale and reset_joints_by_offset.

Fixes #980

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• 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]

This looks good. Thanks for the added functionality