Avoid dying when query is not in cache when using no network mode

[hannaeko]

Currently when running the engine in no network mode if the engine queries for something that is not is the cached data then engine will die. A better option would be to emit a critical message and stop the test.

[tgreenx]

I don't think I agree with what is being asked here. From what I understand, "no_network" mode is a profile parameter which is only relevant when used with pre-recorded data, so for example in unitary tests.

In Engine 4.7.0, this relates to this part of the code, which currently is a croak. https://github.com/zonemaster/zonemaster-engine/blob/8ae6f4bee8dc134256dbb3f15c473310035c3409/lib/Zonemaster/Engine/Nameserver.pm#L438-L442

In normal circonstances Engine will never output such message so a logging message doesn't seem of much use, unless the user specifically sets "no_network" to true in the profile. Moreover, these logging messages are invisible when running unitary tests (i.e. using either perl or prove). On the contrary, I would argue that having an explicit death message (containing the name, query type and name server) is very much useful when dealing with pre-recorded data (e.g. unitary tests).

The only improvement I could see would be to gracefully die (e.g. die Zonemaster::Engine::Exception->new( { message => $message }) instead of the current croak. But I could very well be missing the point.

[matsduf]

@blacksponge, I am not sure what problem you want to solve. "no_network" is primarily used during development.