Added Semantic Descriptors

Contribution by Orange

• Added Semantic Feature
• Added new MgmtObj resources: Battery, Firmware, Memory, Reboot
• Various cleanup & minor bug fixes

MR acceptance checklist

• Contributors have signed the ECA
• Copyrights headers have been added / updated
• Code quality OK
• IP review for all libs (cf. https://github.com/eclipse/dash-licenses & https://www.eclipse.org/projects/handbook/#ip-project-content)
• IP review for contrib as it exceeds 1000 lines (cf. https://github.com/eclipse/dash-licenses & https://www.eclipse.org/projects/handbook/#ip-project-content)
• Build and tests OK