Added specific joint selection to reset_joints_by_offset

[Mitchell-Torok]

Description

The reset_joints_by_offset function resets all the robot joint variables regardless of the ones passed through with asset_cfg.

This change only fixes reset_joints_by_offset however It may also apply to reset_joints_by_scale and others, I just have not tested these other functions.

Fixes #368

Type of change

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

Screenshots

Checklist

• I have run the pre-commit checks with ./orbit.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 run all the tests with ./orbit.sh --test and they pass
• 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