[FEATURE REQUEST] Build epicli image using Dockerfile only (without shell script)

[to-bar]

Is your feature request related to a problem? Please describe.
To build epicli Docker image we use the build-docker.sh shell script. It builds epicli wheel file (distribution package) which is used (copied) in the Dockerfile. The build script has no support for any docker build parameters (like tags or labels) and always creates the epicli image tagged as latest. This requires another task in the build pipeline to tag the image using the target tag. In case of parallel builds there is a risk that the tagging task will label not the right image.

Describe the solution you'd like
Build epicli wheel file as a part of Dockerfile (using multistage builds feature) instead of wrapper script.

[mkyc]

Please remember also about:

• documentation update
• after finish implementation create back port tasks

[to-bar]

Please remember also about:

* after finish implementation create back port tasks

Decided with @przemyslavic to not backport this feature to support branches.

[przemyslavic]

Changes have been tested. The docker image is built correctly both locally and in the CI pipeline. The devcontainer was also rebuilt and no problems were encountered. It was decided not to backport this as it is more of an improvement/feature than a critical fix.