Handle nameservice enabled flags from Mailchain api

[tboeckmann]

Is your feature request related to a problem? Please describe.
In order to reduce nameservice lookup attempts for unsupported protocols, Mailchain introduced nameservice flags on the /protocols endpoint see mailchain#640:

[
    {
        "name": "string",
        "networks": [
            {
                "id": "string",
                "name": "string",
                "nameservice-address-enabled": true,
                "nameservice-domain-enabled": true
            }
        ]
    }
]

Describe the solution you'd like
Add support for this feature in the Mailchain inbox so lookups do not occur unnecessarily.

Describe alternatives you've considered
Requesting Mailchain backend to handle the logic- this could be done at a later stage, but the current proposed fix is sufficient