We now get lots of compile time output like:
```bash
In file included from test/fuzz/addition_overflow.cpp:7:
./test/fuzz/util.h: In member function 'virtual SOCKET FuzzedSock::Get() const':
./test/fuzz/util.h:563:5: warning: no return statement in function returning non-void [-Wreturn-type]
  563 |     }
      |     ^
./test/fuzz/util.h: In member function 'virtual SOCKET FuzzedSock::Release()':
./test/fuzz/util.h:568:5: warning: no return statement in function returning non-void [-Wreturn-type]
  568 |     }
      |     ^
...
```
anywhere `test/fuzz/util.h` is included. Would be great to not have build logs filled with this spam.

This was all present in the CI. i.e https://cirrus-ci.com/task/5500626558779392?command=ci#L4283. 

cc @practicalswift @vasild 
aProvider& fuzzed_data_provider) noexcept
{
    const Network network = fuzzed_data_provider.PickValueInArray({Network::NET_IPV4, Network::NET_IPV6, Network::NET_INTERNAL, Network::NET_ONION});
    CNetAddr net_addr;
    if (network == Network::NET_IPV4) {
        in_addr v4_addr = {};
        v4_addr.s_addr = fuzzed_data_provider.ConsumeIntegral<uint32_t>();
        net_addr = CNetAddr{v4_addr};
    } else if (network == Network::NET_IPV6) {
        if (fuzzed_data_provider.remaining_bytes() >= 16) {
            in6_addr v6_addr = {};
            memcpy(v6_addr.s6_addr, fuzzed_data_provider.ConsumeBytes<uint8_t>(16).data(), 16);
            net_addr = CNetAddr{v6_addr, fuzzed_data_provider.ConsumeIntegral<uint32_t>()};
        }
    } else if (network == Network::NET_INTERNAL) {
        net_addr.SetInternal(fuzzed_data_provider.ConsumeBytesAsString(32));
    } else if (network == Network::NET_ONION) {
        net_addr.SetSpecial(fuzzed_data_provider.ConsumeBytesAsString(32));
    }
    return net_addr;
}
inline CSubNet ConsumeSubNet(FuzzedDataProvider& fuzzed_data_provider) noexcept
{
    return {ConsumeNetAddr(fuzzed_data_provider), fuzzed_data_provider.ConsumeIntegral<uint8_t>()};
}
inline CService ConsumeService(FuzzedDataProvider& fuzzed_data_provider) noexcept
{
    return {ConsumeNetAddr(fuzzed_data_provider), fuzzed_data_provider.ConsumeIntegral<uint16_t>()};
}
inline CAddress ConsumeAddress(FuzzedDataProvider& fuzzed_data_provider) noexcept
{
    return {ConsumeService(fuzzed_data_provider), ConsumeWeakEnum(fuzzed_data_provider, ALL_SERVICE_FLAGS), fuzzed_data_provider.ConsumeIntegral<uint32_t>()};
}
template <bool ReturnUniquePtr = false>
auto ConsumeNode(FuzzedDataProvider& fuzzed_data_provider, const std::optional<NodeId>& node_id_in = std::nullopt) noexcept
{
    const NodeId node_id = node_id_in.value_or(fuzzed_data_provider.ConsumeIntegral<NodeId>());
    const ServiceFlags local_services = ConsumeWeakEnum(fuzzed_data_provider, ALL_SERVICE_FLAGS);
   