Supports detection using only lidar data and modifies the data reading logic.

[JonathanFK981]

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Motivation

I have added support for lidar - only data detection in this new feature. This is to meet the specific requirements of scenarios where only lidar data is available, such as certain autonomous driving applications in environments with limited camera visibility, or in some industrial inspection scenarios where only lidar sensors are deployed. The goal is to enhance the flexibility and applicability of the existing system in handling different data sources for object detection tasks.

Modification

In this PR, we've made several key modifications to support lidar - only data detection. I have updated the data input module to handle and preprocess lidar - only data.

BC-breaking (Optional)

No breaking changes are introduced by this PR.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. I have added unit tests for the new lidar - only data handling functions, including tests for data input validation,
3. If the modification has potential influence on downstream projects, this PR should be tested with downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

All committers have signed the CLA.