The event reset_root_state_uniform had two different logics for setting position and orientation:
```
positions = root_states[:, 0:3] + env.scene.env_origins[env_ids] + rand_samples[:, 0:3]
orientations = math_utils.quat_from_euler_xyz(rand_samples[:, 3], rand_samples[:, 4], rand_samples[:, 5])
```
where the position is set by adding the random samples to the default root states, but the orientation was set as an absolute value.

Both orientation and position are now relative offsets.

## Type of change

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

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] 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 `./isaaclab.sh --test` and they pass
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there