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

#include <streams.h>
#include <txdb.h>
#include <util/memory.h>
#include <util/strencodings.h>
#include <util/string.h>
#include <util/time.h>
#include <util/translation.h>
#include <validation.h>
#include <validationinterface.h>
#include <functional>
const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
FastRandomContext g_insecure_rand_ctx;
static FastRandomContext g_insecure_rand_ctx_temp_path;
static uint256 GetUintFromEnv(const std::string& env_name)
{
    const char* num = std::getenv(env_name.c_str());
    if (!num) return {};
    return uint256S(num);
}
void Seed(FastRandomContext& ctx)
{
    
    static uint256 seed{};
    static const std::string RANDOM_CTX_SEED{"RANDOM_CTX_SEED"};
    if (seed.IsNull()) seed = GetUintFromEnv(RANDOM_CTX_SEED);
    if (seed.IsNull()) seed = GetRandHash();
    LogPrintf("%s: Setting random seed for current tests to %s=%s\n", __func__, RANDOM_CTX_SEED, seed.GetHex());
    ctx = FastRandomContext(seed);
}
std::ostream& operator<<(std::ostream& os, const uint256& num)