RPCs that return detailed information about mempool entries (e.g. `getmempoolentry` and `getrawmempool(verbose=True)` include the fields `fee`, `modifiedfee`, `descendantfees`, and `ancestorfees` which were marked as "DEPRECATED" and replaced with a `fees` object field in #12240 (since v0.17).

We should remove these fields, but first, properly deprecate them using `-deprecatedrpc`.

#### Useful skills:

- basic understanding of Bitcoin Core RPC interface

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{
    if (hash_type_input == "hash_serialized_2") {
        return CoinStatsHashType::HASH_SERIALIZED;
    } else if (hash_type_input == "muhash") {
        return CoinStatsHashType::MUHASH;
    } else if (hash_type_input == "none") {
        return CoinStatsHashType::NONE;
    } else {
        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s is not a valid hash_type", hash_type_input));
    }
}
static RPCHelpMan gettxoutsetinfo()