Updates IMU demo script with renaming changes (#247)

# Description

Updates IMU demo script with renaming changes for Isaac Lab 2.0. Mainly
`omni.isaac.lab` imports have been renamed to `isaaclab`


## Type of change

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

- 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 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

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putting an x character in it

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- [x] I have done this task
- [ ] I have not done this task
-->

scripts/demos/sensors/imu_sensor.py

@@ -7,7 +7,7 @@
 
 import argparse
 
-from omni.isaac.lab.app import AppLauncher
+from isaaclab.app import AppLauncher
 
 # add argparse arguments
 parser = argparse.ArgumentParser(description="Tutorial on adding sensors on a robot.")
@@ -25,16 +25,16 @@ simulation_app = app_launcher.app
 
 import torch
 
-import omni.isaac.lab.sim as sim_utils
-from omni.isaac.lab.assets import AssetBaseCfg
-from omni.isaac.lab.scene import InteractiveScene, InteractiveSceneCfg
-from omni.isaac.lab.sensors import ImuCfg
-from omni.isaac.lab.utils import configclass
+import isaaclab.sim as sim_utils
+from isaaclab.assets import AssetBaseCfg
+from isaaclab.scene import InteractiveScene, InteractiveSceneCfg
+from isaaclab.sensors import ImuCfg
+from isaaclab.utils import configclass
 
 ##
 # Pre-defined configs
 ##
-from omni.isaac.lab_assets.anymal import ANYMAL_C_CFG  # isort: skip
+from isaaclab_assets.robots.anymal import ANYMAL_C_CFG  # isort: skip
 
 
 @configclass