# Description

This MR does the following:

* Adds the function `omni.isaac.orbit.utils.math.quat_unique` to
standardize quaternion representations, i.e.
  always have a non-negative real part.
* Adds events terms for randomizing mass by scale, simulation joint
properties (stiffness, damping, armature,
  and friction)
* Adds clamping of joint positions and velocities in event terms for
resetting joints. The simulation does not
throw an error if the set values are out of their range. Hence, users
are expected to clamp them before setting.
* Fixes
`omni.isaac.orbit.envs.mdp.ExponentialMovingAverageJointPositionAction`
to smoothen the actions
  at environment frequency instead of simulation frequency.

## Type of change

- Bug fix (non-breaking change which fixes an issue)
- New feature (non-breaking change which adds functionality)
- Breaking change (fix or feature that would cause existing
functionality to not work as expected)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have run all the tests with `./orbit.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