[+] Added a check to ensure that the decree is not set to NULL before determining whether mapping is working and clearing the decree.

Sign structure checking bugfixes

[*] Fixed a segmentation error for the srv_xchange order status -net <net_name> -order <order_hash> command. The fact is that now the dap_uint256_to_char function returns a pointer to static memory in local thread and there is no need to clear it.

[*] Fixed a bug with the fact that the address pointers were not set to the conditional output of the transaction, the previous conditional output of the transaction and the index of this output.