feat: implementation of docker compose replica for gst dlstreamer

PR Checklist

[x] Added label to the Pull Request for easier discoverability and search
[x] Commit Message meets guidelines as indicated in the URL https://github.com/intel-retail/retail-use-cases/blob/main/CONTRIBUTING.md
[x] Every commit is a single defect fix and does not mix feature addition or changes
[ ] Unit Tests have been added for new changes
[x] Updated Documentation as relevant to the changes
[ ] All commented code has been removed
[ ] If you've added a dependency, you've ensured license is compatible with repository license and clearly outlined the added dependency.
[ ] PR change contains code related to security
[ ] PR introduces changes that breaks compatibility with other modules (If YES, please provide details below)

git clone this PR
if first time, you need to get the content of submodules via running make update-submodules

(cd use-cases/dlstreamer; make build)

run one gst dlstreamer pipeline and use the default object detection only (yolov5s.sh)
```
make run-gst
```
run three gst dlstreamer pipelines and use the default object detection only (yolov5s.sh)
```
PIPELINE_COUNT=3 make run-gst
```
run two gst dlstreamer pipelines and use the object detection with classification (yolov5s_effnetb0.sh)
```
PIPELINE_SCRIPT=yolov5s_effnetb0.sh PIPELINE_COUNT=2 make run-gst
```
shutdown Docker containers
```
make down-gst
```
clean up the output results
```
make clean-results
```