Add so-100 envs

[ashwinvkNV]

Description

This pull request adds SO-100 robot support and Pink IK relative mode functionality.

Changes:

• SO-100 Robot: Added robot configuration and stack manipulation environments
• Pink IK Relative Mode: Added delta-based control mode (dx, dy, dz, droll, dpitch, dyaw)
• Teleoperation: Added configurable sensitivity parameters for record_demos.py
• Mimic Integration: Added SO-100 support for demonstration recording

Technical Details:

• use_relative_mode flag enables 6-DOF delta control vs 7-DOF absolute mode
• set_targets_from_joint_positions method for target initialization
• --pos_sensitivity and --rot_sensitivity CLI arguments for teleoperation
• Environment configs for joint position, Pink IK relative, and visuomotor
• Custom MDP events for SO-100 object randomization

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

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