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.
throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, "Cannot set a new HD seed while still in Initial Block Download");
    }
    LOCK2(cs_main, pwallet->cs_wallet);
    
    if (!pwallet->IsHDEnabled()) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Cannot set a HD seed on a non-HD wallet. Start with -upgradewallet in order to upgrade a non-HD wallet to HD");
    }
    EnsureWalletIsUnlocked(pwallet);
    bool flush_key_pool = true;
    if (!request.params[0].isNull()) {
        flush_key_pool = request.params[0].get_bool();
    }
    CPubKey master_pub_key;
    if (request.params[1].isNull()) {
        master_pub_key = pwallet->GenerateNewSeed();
    } else {
        CKey key = DecodeSecret(request.params[1].get_str());
        if (!key.IsValid()) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid private key");
        }
        if (HaveKey(*pwallet, key)) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Already have this key (either as an HD seed or as a loose private key)");
        }
        master_pub_key = pwallet->DeriveNewSeed(key);
    }
    pwallet->SetHDSeed(master_pub_key);
    if (flush_key_pool) pwallet->NewKeyPool();
    return NullUniValue;
}
void AddKeypathToMap(const CWallet* pwallet, const CKeyID& keyID, std::map<CPubKey, KeyOriginInfo>& hd_keypaths)