Add a REST APIs support for IOVIsor module

Add a REST APIs support for IOVIsor module

- provide aaa authentication
- path is: /controller/sb/iovisor/{SERVICE}

For now we have one service being: /policies
Through this one we will POST a list of policies for the
IOVisor module to GET.

To play with thee REST interface, you can use this
postman collection: https://www.getpostman.com/collections/3b1fe6ef1ec0ead72ee7

Another patch will implement the POST correctly

Change-Id: I5186df6b5d0501dca8b244bfd04e22dd54649b40
Signed-off-by: adetalhouet <adetalhouet@inocybe.com>