message: More details on error
diff: #include "nodetypes.h"
  #include <algorithm>
  +#include <fmt/format_header_only.h>
  namespace ccf
  {
  @@ -75,7 +76,12 @@ namespace ccf
  auto& n2n_channel = channels->get(t.from_node);
  if (!n2n_channel.verify(hdr, asCb(t)))
  - throw std::logic_error("Invalid authenticated node2node message");
  + {
  + throw std::logic_error(fmt::format(
  + "Invalid authenticated node2node message from node {} (size: {})",
  + t.from_node,
  + size));
  + }
  return t;
  }
  @@ -111,7 +117,12 @@ namespace ccf
  auto& n2n_channel = channels->get(t.from_node);
  if (!n2n_channel.decrypt(hdr, asCb(t), {data, size}, plain))
  - throw std::logic_error("Invalid encrypted node2node message");
  + {
  + throw std::logic_error(fmt::format(
  + "Invalid authenticated node2node message from node {} (size: {})",
  + t.from_node,
  + size));
  + }
  return std::make_pair(t, plain);
  }
  