Add option to modify batch size in GST pipelines

[brian-intel]

No description provided.

[gsilva2016]

Dev completed https://github.com/gsilva2016/vision-self-checkout/tree/bs8. Awaiting feedback and validation from customer before submitting a pull request

[brian-intel]

Update OVMS config with dynamic batch size

https://github.com/intel-retail/automated-self-checkout/blob/main/configs/opencv-ovms/models/2022/config_template.json
https://github.com/intel-retail/automated-self-checkout/blob/main/configs/opencv-ovms/models/2022/update_server_device.py

[jim-wang-intel]

• maybe add BATCH_SIZE env into env-file and the end user can do the environment variable override to customize the batch size

[mechris1]

• GST pipeline script update
  CAPI pipeline update (won't do)
  GRPC pipeline update (won't do)

[jim-wang-intel]

After discussed with @brian-intel , for release 2.1, we will only do gst pipeline script update for batch_size as currently the grpc demo code from openvino itself doesn't have batch available. Also, batch_size is model specific; not every model can have batching.