CidrPrefix config parameter to support IP range(s)

[zolug]

Currently a network has to be specified that the provided IPAM will assign addresses from.
Besides using a whole network it could be beneficial if the address pool could be configured by defining an IP range or IP ranges.

Such feature would greatly complement networkservicemesh/sdk-vpp#634.
E.g. let's consider two independent NSM services provided by two separate Remote VLAN NSEs using the same VLAN ID and master interface and "sharing" the same network. To avoid duplicated IPs the network could be split into IP ranges distributed between NSEs.

[denis-tingaikin]

@zolug, to separate two ippools could be used, exclude-prefix mechanics.

Currently, we have two fields that we designed for these cases.

1. https://github.com/networkservicemesh/api/blob/main/pkg/api/networkservice/connectioncontext.proto#L69
2. https://github.com/networkservicemesh/api/blob/main/pkg/api/networkservice/connectioncontext.proto#L73

So we probably could re-use https://github.com/networkservicemesh/sdk/tree/main/pkg/networkservice/common/excludedprefixes to solve the problem

OR we could implement a chain element for extra-exclude-preofix requests https://github.com/networkservicemesh/api/blob/main/pkg/api/networkservice/connectioncontext.proto#L73

Feel free to share ur thoughts and correct me if I get something wrong :)

/cc @edwarnicke