Functional tests for otn-switch-end2end in 2.2.1

Create a new functional test suite that tests two otn-switch use cases at 100GE:

• when two otn-switch are used as end-point of the service
• when a third otn-switch is used as intermediate / electrical otn regenererator along the end-to-end path.

For both uses-cases, the 100GE service (over not structured ODU4) is carried over one or two OTU4 otn links.