Added action recognition pipeline and Python bindings

[eresh-mittal]

This Merge Request introduces the following key contributions to the DeepStream Python Apps project:

Action Recognition Pipeline:

Implemented a 3D Action Recognition pipeline in Python using DeepStream plugins.
The pipeline integrates multiple components to detect and classify human actions in video streams.

Developed custom Python bindings for the GstNvDsPreProcessBatchMeta and NvDsRoiMeta plugin to enable preprocessing of video batches before feeding them into the action recognition model.

The implementation has been tested on various video inputs and is compatible with the latest version of DeepStream.
The code follows the existing coding standards and structure of the DeepStream Python Apps project.

[nv-zhliu]

Dear @eresh-mittal, thank you very much for your contribution. We are looking for the best way to incorporate this since our repo is not set up to directly accept PRs. Thanks for your patience.