Add NameService UT

[cloud8little]

No description provided.

[cloud8little]

@erikzhang do we allow these data to be stored as IPv4 name service? I do not think they are valid ipv4 address. but currently they are valid values from testing result.

            setRecord_ret = Check_SetRecord(snapshot, domain, RecordType.A, "0.0.256", from, persistingBlock);
            setRecord_ret.Should().BeFalse();

            setRecord_ret = Check_SetRecord(snapshot, domain, RecordType.A, "0.257", from, persistingBlock);
            setRecord_ret.Should().BeFalse();

            setRecord_ret = Check_SetRecord(snapshot, domain, RecordType.A, "257", from, persistingBlock);
            setRecord_ret.Should().BeFalse();

[erikzhang]

Please check #2262

[cloud8little]

wait for #2262

[erikzhang]

@cloud8little Merge?

[cloud8little]

good to merge