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.
if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() < 1 || request.params.size() > 3)
        throw std::runtime_error(
            "signrawtransactionwithwallet \"hexstring\" ( [{\"txid\":\"id\",\"vout\":n,\"scriptPubKey\":\"hex\",\"redeemScript\":\"hex\"},...] sighashtype )\n"
            "\nSign inputs for raw transaction (serialized, hex-encoded).\n"
            "The second optional argument (may be null) is an array of previous transaction outputs that\n"
            "this transaction depends on but may not yet be in the block chain.\n"
            + HelpRequiringPassphrase(pwallet) + "\n"
            "\nArguments:\n"
            "1. \"hexstring\"                      (string, required) The transaction hex string\n"
            "2. \"prevtxs\"                        (string, optional) An json array of previous dependent transaction outputs\n"
            "     [                              (json array of json objects, or 'null' if none provided)\n"
            "       {\n"
            "         \"txid\":\"id\",               (string, required) The transaction id\n"
            "         \"vout\":n,                  (numeric, required) The output number\n"
            "         \"scriptPubKey\": \"hex\",     (string, required) script key\n"
            "         \"redeemScript\": \"hex\",     (string, required for P2SH or P2WSH) redeem script\n"
            "         \"amount\": value            (numeric, required) The amount spent\n"
            "       }\n"
            "       ,...\n"
            "    ]\n"
            "3. \"sighashtype\"                    (string, optional, default=ALL) The signature hash type. Must be one of\n"
            "       \"ALL\"\n"
            "       \"NONE\"\n"
            "       \"SINGLE\"\n"
            "       \"ALL|ANYONECANPAY\"\n"
            "       \"NONE|ANYONECANPAY\"\n"
            "       \"SINGLE|ANYONECANPAY\"\n"