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 || request.params.size() > 2)
        throw std::runtime_error(
            "getreceivedbyaddress \"address\" ( minconf )\n"
            "\nReturns the total amount received by the given address in transactions with at least minconf confirmations.\n"
            "\nArguments:\n"
            "1. \"address\"         (string, required) The bitcoin address for transactions.\n"
            "2. minconf             (numeric, optional, default=1) Only include transactions confirmed at least this many times.\n"
            "\nResult:\n"
            "amount   (numeric) The total amount in " + CURRENCY_UNIT + " received at this address.\n"
            "\nExamples:\n"
            "\nThe amount from transactions with at least 1 confirmation\n"
            + HelpExampleCli("getreceivedbyaddress", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\"") +
            "\nThe amount including unconfirmed transactions, zero confirmations\n"
            + HelpExampleCli("getreceivedbyaddress", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" 0") +
            "\nThe amount with at least 6 confirmations\n"
            + HelpExampleCli("getreceivedbyaddress", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" 6") +
            "\nAs a JSON-RPC call\n"
            + HelpExampleRpc("getreceivedbyaddress", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", 6")
       );