libevent seems to have invaded `libbitcoin_common` via `url.cpp`

`url.cpp` is used only from `test/fuzz/string.cpp` and `wallet/rpcwallet.cpp`

libevent should only be required for bitcoind, bitcoin-cli and (due only to the hack of passing wallet names) bitcoin-qt

{
#ifdef WIN32
    util::WinCmdLineArgs winArgs;
    std::tie(argc, argv) = winArgs.get();
#endif
    SetupEnvironment();
    RandomInit();
    try {
        if (!WalletAppInit(argc, argv)) return EXIT_FAILURE;
    } catch (const std::exception& e) {
        PrintExceptionContinue(&e, "WalletAppInit()");
        return EXIT_FAILURE;
    } catch (...) {
        PrintExceptionContinue(nullptr, "WalletAppInit()");