Update PED file for OSM deployment requirements

[qarawlus]

Update the tng-bench ped files and create a version that provides the correct parameters to deploy a benchmarking experiment in OSM.

Initial thoughts:
The file should have the following main sections:

• VNFD identifier: the filename or the OSM VNFD identifier. This is the part where the virtual network function is defined.
• NSD Identifier (optional): If left blank, tng-bench should generate this based on the information from the probes section in the ped. The NSD provides information on how the VNF or VNF chain is connected internally, and possibly to the probes.
• Type of experiment.
• Probes: How many probes to connect to the VNF and how.

This list might be updated later on. Updates will be clearly marked.

DEADLINE: 15.09.2019

[qarawlus]

Update: Now depends partly on a solid VNFD and NSD example generated from #9