Different wallets may be used for different purposes.  When a notification is triggered, we get the TXID but don't know which wallet is involved.  It would be useful to have different walletnotify actions depending on which wallet is involved by the transaction.

It could be used like (bitcoin.conf):

`walletnotify.walletname=action %s`

Or maybe a more simple and flexible (dynamic-wallets compatible) way:

`walletnotify=action %s %w`

where %w is the name of the wallet.  This way, notify action (and not Bitcoin Core) is responsible for choosing the right action depending on the wallet and it is easier to RPC query the good wallet (ie gettransaction).

*/
    bool SoftSetArg(const std::string& strArg, const std::string& strValue);
    /**
     * Set a boolean argument if it doesn't already have a value
     *
     * @param strArg Argument to set (e.g. "-foo")
     * @param fValue Value (e.g. false)
     * @return true if argument gets set, false if it already had a value
     */
    bool SoftSetBoolArg(const std::string& strArg, bool fValue);
    
    
    void ForceSetArg(const std::string& strArg, const std::string& strValue);
    /**
     * Returns the appropriate chain name from the program arguments.
     * @return CBaseChainParams::MAIN by default; raises runtime error if an invalid combination is given.
     */
    std::string GetChainName() const;
    /**
     * Add argument
     */
    void AddArg(const std::string& name, const std::string& help, unsigned int flags, const OptionsCategory& cat);
    /**
     * Add many hidden arguments
     */
    void AddHiddenArgs(const std::vector<std::string>& args);
    /**
     * Clear available arguments
     */
    void ClearArgs() {