The `generate` RPC method:
- was introduced in 2010
- is now only used for testing
- reaches across multiple components (wallet, mining)

I propose we remove the wallet `generate` RPC method and update all tests to use the `generatetoaddress` RPC method. We can do this non-invasively in the test framework by adding a `generate` method to `TestNode` so that the individual tests do not need to be updated. We could also add a `generate` alias to the `generatetoaddress` RPC method.

Doing this removes a wallet->server dependency and simplifies the wallet->server interface (#10973).

I'm opening this issue before implementing in case anyone has objections.
strWalletPass = request.params[0].get_str().c_str();
    
    int64_t nSleepTime = request.params[1].get_int64();
    
    if (nSleepTime < 0) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Timeout cannot be negative.");
    }
    
    constexpr int64_t MAX_SLEEP_TIME = 100000000; 
    if (nSleepTime > MAX_SLEEP_TIME) {
        nSleepTime = MAX_SLEEP_TIME;
    }
    if (strWalletPass.length() > 0)
    {
        if (!pwallet->Unlock(strWalletPass)) {
            throw JSONRPCError(RPC_WALLET_PASSPHRASE_INCORRECT, "Error: The wallet passphrase entered was incorrect.");
        }
    }
    else
        throw std::runtime_error(
            "walletpassphrase <passphrase> <timeout>\n"
            "Stores the wallet decryption key in memory for <timeout> seconds.");
    pwallet->TopUpKeyPool();
    pwallet->nRelockTime = GetTime() + nSleepTime;
    RPCRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), std::bind(LockWallet, pwallet), nSleepTime);
    return NullUniValue;
}
static UniValue walletpassphrasechange(const JSONRPCRequest& request)