Whenever -blocksonly is specified, there is implicitly a zero size mempool. However, there is still a non-zero value for -maxmempool which will be shared with dbcache, leading to 300 MB extra usage. Fix this.
using kernel::ValidationCacheSizes;
using node::ApplyArgsManOptions;
using node::CacheSizes;
using node::CalculateCacheSizes;
using node::DEFAULT_PERSIST_MEMPOOL;
using node::DEFAULT_PRINTPRIORITY;
using node::DEFAULT_STOPAFTERBLOCKIMPORT;
using node::LoadChainstate;
using node::MempoolPath;
using node::ShouldPersistMempool;
using node::NodeContext;
using node::ThreadImport;
using node::VerifyLoadedChainstate;
using node::fPruneMode;
using node::fReindex;
using node::nPruneTarget;
static constexpr bool DEFAULT_PROXYRANDOMIZE{true};
static constexpr bool DEFAULT_REST_ENABLE{false};
static constexpr bool DEFAULT_I2P_ACCEPT_INCOMING{true};
#ifdef WIN32
#define MIN_CORE_FILEDESCRIPTORS 0
#else
#define MIN_CORE_FILEDESCRIPTORS 150
#endif
static const char* DEFAULT_ASMAP_FILENAME="ip_asn.map";
**
 * The PID file facilities.
 *
static const char* BITCOIN_PID_FILENAME = "bitcoind.pid";
static fs::path GetPidFile(const ArgsManager& args)