This change moves the configuration of the teleop device from the end
user scripts (record_demos.py, teleop_se3.py, etc) to the env config
itself. This allows the task to specify what teleop devices are
supported along with the per env configuration of supported teleop
device.

Example teleop config inside of the env config:
```
        self.teleop_devices = DevicesCfg(
            devices={
                "handtracking": OpenXRDeviceCfg(
                    retargeters=[
                        Se3RelRetargeterCfg(
                            bound_hand=OpenXRDevice.TrackingTarget.HAND_RIGHT,
                            zero_out_xy_rotation=True,
                            use_wrist_rotation=False,
                            use_wrist_position=True,
                            delta_pos_scale_factor=10.0,
                            delta_rot_scale_factor=10.0,
                            sim_device=self.sim.device,
                        ),
                        GripperRetargeterCfg(
                            bound_hand=OpenXRDevice.TrackingTarget.HAND_RIGHT, sim_device=self.sim.device
                        ),
                    ],
                    sim_device=self.sim.device,
                    xr_cfg=self.xr,
                ),
                "keyboard": Se3KeyboardCfg(
                    pos_sensitivity=0.05,
                    rot_sensitivity=0.05,
                    sim_device=self.sim.device,
                ),
            }
        )
```
<!--
Thank you for your interest in sending a pull request. Please make sure
to check the contribution guidelines.

Link:
https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html
-->

Please include a summary of the change and which issue is fixed. Please
also include relevant motivation and context.
List any dependencies that are required for this change.

Fixes # (issue)

<!-- As a practice, it is recommended to open an issue to have
discussions on the proposed pull request.
This makes it easier for the community to keep track of what is being
developed or added, and if a given feature
is demanded by more than one party. -->

<!-- As you go through the list, delete the ones that are not
applicable. -->

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

Please attach before and after screenshots of the change if applicable.

<!--
Example:

| Before | After |
| ------ | ----- |
| _gif/png before_ | _gif/png after_ |

To upload images to a PR -- simply drag and drop an image while in edit
mode and it should upload the image directly. You can then paste that
source into the above before/after sections.
-->

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.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 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

<!--
As you go through the checklist above, you can mark something as done by
putting an x character in it

For example,
- [x] I have done this task
- [ ] I have not done this task
-->

---------
Signed-off-by: Kelly Guo <kellyg@nvidia.com>
Co-authored-by: Kelly Guo <kellyguo123@hotmail.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>