resolve dependencies for CI/CD build

There are some dependencies in the Dockerfile that are currently resolved as:

RUN git clone https://github.com/somnonetz/snet-asclepios-search /tmp/asclepios-search && cd /tmp/asclepios-search && git checkout ${ASCLEPIOS_SEARCH_VER} && npm ci && npm run js-build && npm run css-build

These need to be resolved properly, e.g. submodules or publishing artifacts of the projects which this one depends on.

definition of done:

• choose strategy --> use submodules because this is easy to implement
• implement
  • https://api.bitbucket.org/2.0/repositories/xnatdev/xnat-web/downloads/xnat-web-${XNAT_VER}.war
  • https://github.com/Australian-Imaging-Service/xnat-openid-auth-plugin
  • https://gitlab.com/indie-sleep-demo/snet-asclepios-plugin.git
  • https://gitlab.com/indie-sleep-demo/snet-asclepios-search.git
  • https://gitlab.com/indie-sleep-demo/copla-editor.git
• adjust Dockerfile to use artifacts from previous build jobs
• test
• announce to colleagues if necessary
• write documentation

Hints:

• This includes project from third parties, like xnat-openid-auth-plugin.