message: fuzzer: Implement basic parser fuzzer
diff: extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t data_size) noexcept
  {
  - (void)data;
  - (void)data_size;
  + try
  + {
  + fizzy::parse({data, data_size});
  + }
  + catch (const fizzy::parser_error&)
  + {
  + }
  return 0;
  }
  