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

[kellyguo11]

would this change affect other environments that use reset_joints_by_offset? such as ant, humanoid, cabinet

[Mayankm96]

This environment file isn't a place to have this feature as a unit test IMO. We're changing the way the environment operates.

[Mayankm96]

Isn't this a slower operation since you are copying over the data twice (first here by setting into joint_pos_all and then it is again done inside the method). Why not keep it cleaner and just operate over the asset_cfg.joint_indices in the whole thing?

Something like:

    # extract the used quantities (to enable type-hinting)
    asset: Articulation = env.scene[asset_cfg.name]
    command_term: PhaseCommand = env.command_manager.get_term(command_name)

    # broadcast env_ids if needed to allow double indexing
    if env_ids != slice(None) and asset_cfg.joint_ids != slice(None):
        env_ids = env_ids[:, None]

    # read state
    ....

    # clamp joint pos to limits
    joint_pos_limits = asset.data.soft_joint_pos_limits[env_ids, asset_cfg.joint_ids]
    joint_pos = joint_pos.clamp_(joint_pos_limits[..., 0], joint_pos_limits[..., 1])
    # clamp joint vel to limits
    joint_vel_limits = asset.data.soft_joint_vel_limits[env_ids, asset_cfg.joint_ids]
    joint_vel = joint_vel.clamp_(-joint_vel_limits, joint_vel_limits)

    # make sure env ids dimensions are compatible
    if env_ids != slice(None) and asset_cfg.joint_ids != slice(None):
        env_ids = env_ids.squeeze(1)
    # set into the physics simulation
    asset.write_joint_state_to_sim(joint_pos, joint_vel, env_ids=env_ids, joint_ids=asset_cfg.joint_ids)