Integrated basic slicing skeleton.

Compute:
- added support for Slice creation when VPLS service is requested instead of VPWS

Context:
- minor improvements in client class logging
- added slice events to EventsCollector
- minor bug fixes in SliceModel

Interdomain:
- Implemented basic workflow

Monitoring:
- fixed requirements versions

Service:
- minor improvements in client and server logging

Slice:
- Implemented basic workflow

OECC/PSC'22 functional test:
- updated test objects
- updated deployment script
- updated exposed services