Add caching for docker layers and build caches for UI End-to-End tests

Currently the docker build for End-to-End tests on GH Actions takes a very long time building the Debezium UI container (>=80% of the total build time).
The reason seems to be that the docker build cache and intermediate layers are not cached. Sometimes downloading dependent image layers can be slow.
Also we might face issues with Docker Hub request limits.
For this we should add caching for docker build cache and image layers.
See:
https://github.com/docker/setup-buildx-action
https://evilmartians.com/chronicles/build-images-on-github-actions-with-docker-layer-caching (see section "Finally, getting some action")