Integrate base CI steps

Add basic CI steps for CentOS 7:

• compilation of COTS
• compilation of Maja
• compilation of Maja package
• run TVA tests
• "heavy" pipeline for TV tests:
  • Triggered by a schedule every day on develop
  • can be triggered on a specific branch using Web UI "Run Pipeline"
  • all TV run on CentOS 7 in 7 hours
  • only one test failing: pyTv-S2-L2NOMINAL-001-SENTINEL2-ALGO_COMP_IMAGE