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.
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() != 1)
        throw std::runtime_error(
            "getaddressesbylabel \"label\"\n"
            "\nReturns the list of addresses assigned the specified label.\n"
            "\nArguments:\n"
            "1. \"label\"  (string, required) The label.\n"
            "\nResult:\n"
            "{ (json object with addresses as keys)\n"
            "  \"address\": { (json object with information about address)\n"
            "    \"purpose\": \"string\" (string)  Purpose of address (\"send\" for sending address, \"receive\" for receiving address)\n"
            "  },...\n"
            "}\n"
            "\nExamples:\n"
            + HelpExampleCli("getaddressesbylabel", "\"tabby\"")
            + HelpExampleRpc("getaddressesbylabel", "\"tabby\"")
        );
    LOCK(pwallet->cs_wallet);