fix flow chart and add error validation section

topics/icrc_X_multiple_canister_call.md

@@ -71,6 +71,7 @@ Beside errors defined in [ICRC-25](./icrc_25_signer_interaction_standard.md#erro
 In order to have a sequence execution we have to create another method to parse the canister and return the boolean. And this is another new ICRC standard.
 
 The method will take the `contentMap` from previous request and parse it and return is that success call or not.
+
 This can be a fixed `contentMap` for the canister call
 
 ```
@@ -81,9 +82,9 @@ This can be a fixed `contentMap` for the canister call
 
 // signer received payload
 {
-          "contentMap": "2dn3p2NhcmdYTkRJREwEbXtuAGwCs7DawwNorYbKgwUBbAP7ygECot6U6wYB2KOMqA19AQMBHVfs7SoKuxOJdX37k7sBJsPALWEo5ayflizuaH0CAADIAWtjYW5pc3Rlcl9pZEoAAAAAAcDR1wEBbmluZ3Jlc3NfZXhwaXJ5GxeNX/65y4YAa21ldGhvZF9uYW1laHRyYW5zZmVyZW5vbmNlUFF4+hAimFhoqkdUcIchz0xscmVxdWVzdF90eXBlZGNhbGxmc2VuZGVyWB1q63Snu+4C5/fpWFu4nq1IpZxCYDEYA8XSPqPfAg==",
-          "certificate": "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"
-        }
+  "contentMap": "2dn3p2NhcmdYTkRscmVxdWVzdF90eXBlZGNhbGxmc2VuZGVyWB1q63Snu+4C5/fpWFu4nq1IpZxCYDEYA8XSPqPfAg==",
+  "certificate": "..."
+}
 ```
 
 ## Flow