Add motr rpm build CI job

Adds a manual CI job to run the cortx-motr, cortx-motr-utils, and cortx-hare (if on x86_64) builds and export the RPMs and the missing libmotr-ut.so* to an artifact.

This will be changed to export to the package repo once possible

Artifacts can be consumed with:

motr_rpm_download:
  stage: .pre
  script:
    - 'curl -L --output rpms.zip --header "JOB-TOKEN: $CI_JOB_TOKEN" "https://git.ichec.ie/api/v4/projects/418/jobs/artifacts/123-motr-ci-build/download?job=motr_rpm_build"'
    - unzip -q rpms.zip
  artifacts:
    name: "motr-rpms"
    expire_in: 1 day
    paths:
      - ${CI_PROJECT_DIR}/motr-${CI_RUNNER_EXECUTABLE_ARCH}-rpms

Closes #123 (closed)