Allow multiple groups of transactions as per ARC-0001

[kieranroneill]

Summary

When signing multiple transactions, an oversight was made in the understanding of the ARC-0001 spec, namely, there can be multiple groups of transactions.

See ARC-0001#Group Validation.

Steps to produce

• Create multiple groups of transactions
• Send to Kibisis to be signed

Expected Results

• The User is presented with the groups of transactions

Actual Results

• Add error, such as the below, is returned:

"the computed group id "qbbpomwq7jkf6tef2iqeooz/rz7u5gb+icwx/a7qrrg=" does not match the assigned transaction group ids ["ro3sofdzqilctl8wrb5vwexbvtfv42ozg1rqkfpyeuk=","ro3sofdzqilctl8wrb5vwexbvtfv42ozg1rqkfpyeuk=","ro3sofdzqilctl8wrb5vwexbvtfv42ozg1rqkfpyeuk=","ro3sofdzqilctl8wrb5vwexbvtfv42ozg1rqkfpyeuk=","ro3sofdzqilctl8wrb5vwexbvtfv42ozg1rqkfpyeuk=","vdf2ri4v64me1g7f1ljw6tvamsavixenqjucdtmwhaa=","vdf2ri4v64me1g7f1ljw6tvamsavixenqjucdtmwhaa=","vdf2ri4v64me1g7f1ljw6tvamsavixenqjucdtmwhaa="]"