OTUC2 & OTUC3 in Renderer

We should be able to handle intermediate rate use cases (OTUC3/otsi, OTUC2/otsi) to address potential upcoming use cases such as 2x100GE over an OTUC2, in case an OTUC4 can not be created between 2 points (performance issue). The 2x100GE over an an OTUC2 is planned for OFC demo.

Intermediate rates need to be handled. As a first step, propose to handle OTUC2 and OTUC3 in Renderer. This services may be triggered when the Service handler will be updated

Acceptance criteria : The code does not bring regression, and is submitted to review. Junit test associated with the new added functions are also provided to limit the technical debt. Functionnal test are provided so that end 2 end tests can be built in a next step.