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.
"\nResult:\n"
            "[ blockhashes ]     (array) hashes of blocks generated\n"
            "\nExamples:\n"
            "\nGenerate 11 blocks\n"
            + HelpExampleCli("generate", "11")
        );
    }
    if (!IsDeprecatedRPCEnabled("generate")) {
        throw JSONRPCError(RPC_METHOD_DEPRECATED, "The wallet generate rpc method is deprecated and will be fully removed in v0.19. "
            "To use generate in v0.18, restart bitcoind with -deprecatedrpc=generate.\n"
            "Clients should transition to using the node rpc method generatetoaddress\n");
    }
    int num_generate = request.params[0].get_int();
    uint64_t max_tries = 1000000;
    if (!request.params[1].isNull()) {
        max_tries = request.params[1].get_int();
    }
    std::shared_ptr<CReserveScript> coinbase_script;
    pwallet->GetScriptForMining(coinbase_script);
    
    if (!coinbase_script) {
        throw JSONRPCError(RPC_WALLET_KEYPOOL_RAN_OUT, "Error: Keypool ran out, please call keypoolrefill first");
    }
    
    if (coinbase_script->reserveScript.empty()) {
        throw JSONRPCError(RPC_INTERNAL_ERROR, "No coinbase script available");
    }
    return generateBlocks(coinbase_script, num_generate, max_tries, true);
}
UniValue rescanblockchain(const JSONRPCRequest& request)