bandwidth plugin: possibility to exclude some subnets from traffic shapping

[Raphaël Glon]

Hello

I've pushed the following pr on the cni plugins repo to implement the possibility to exclude some subnets from traffic shapping in the bandwidth plugin

https://github.com/containernetworking/plugins/pull/921

Changes are big for a single pr, but mainly concern unit/integration tests. I had no choice but to change the qdisc type (tbf -> htb) to be able to do so

Who should I add as a reviewer on this ?

Happy to discuss about it :)

Regards