fix(group): Better error logs for MsgExec

[amaury1093]

Description

ref: #10968

In case of MsgExec failure, we added a logs field in the event. While debugging #11679, I noticed these logs were not clear.

Before, the event on MsgExec failure looks like:

{
          "key": "logs",
          "value": "\"proposal execution failed on proposal 2, because of error \\ngithub.com/cosmos/cosmos-sdk/x/bank/keeper.BaseSendKeeper.subUnlockedCoins\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/bank/keeper/send.go:192\\ngithub.com/cosmos/cosmos-sdk/x/bank/keeper.BaseSendKeeper.SendCoins\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/bank/keeper/send.go:137\\ngithub.com/cosmos/cosmos-sdk/x/bank/keeper.msgServer.Send\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/bank/keeper/msg_server.go:46\\ngithub.com/cosmos/cosmos-sdk/x/bank/types._Msg_Send_Handler.func1\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/bank/types/tx.pb.go:324\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.(*MsgServiceRouter).RegisterService.func2.1\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/msg_service_router.go:114\\ngithub.com/cosmos/cosmos-sdk/x/bank/types._Msg_Send_Handler\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/bank/types/tx.pb.go:326\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.(*MsgServiceRouter).RegisterService.func2\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/msg_service_router.go:118\\ngithub.com/cosmos/cosmos-sdk/x/group/keeper.Keeper.doExecuteMsgs\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/group/keeper/proposal_executor.go:40\\ngithub.com/cosmos/cosmos-sdk/x/group/keeper.Keeper.Exec\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/group/keeper/msg_server.go:752\\ngithub.com/cosmos/cosmos-sdk/x/group._Msg_Exec_Handler.func1\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/group/tx.pb.go:2069\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.(*MsgServiceRouter).RegisterService.func2.1\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/msg_service_router.go:114\\ngithub.com/cosmos/cosmos-sdk/x/group._Msg_Exec_Handler\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/group/tx.pb.go:2071\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.(*MsgServiceRouter).RegisterService.func2\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/msg_service_router.go:118\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.runMsgsTxHandler.runMsgs\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/run_msgs.go:67\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.runMsgsTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/run_msgs.go:36\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.tipsTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/tips.go:36\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.consumeBlockGasHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/block_gas.go:47\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.branchAndRun\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/branch_store.go:45\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.branchStoreHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/branch_store.go:29\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.incrementSequenceTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/sigverify.go:604\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.sigVerificationTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/sigverify.go:532\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.sigGasConsumeTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/sigverify.go:380\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.validateSigCountTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/sigverify.go:213\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.setPubKeyTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/sigverify.go:142\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.deductFeeTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/fee.go:124\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.consumeTxSizeGasTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/basic.go:322\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.validateMemoTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/basic.go:207\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.txTimeoutHeightTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/basic.go:141\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.validateBasicTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/basic.go:79\\ngithub.com/cosmos/cosmos-sdk/x/auth/middleware.rejectExtensionOptionsTxHandler.DeliverTx\\n\\t/Users/amaury/Workspace/regen/cosmos-sdk/x/auth/middleware/ext.go:76\\nmessage \\\"from_address:\\\\\\\"cosmos142498n8sya3k3s5jftp7dujuqfw3ag4tpzc2ve45ykpwx6zmng8sn2mzmw\\\\\\\" to_address:\\\\\\\"cosmos1uce9j2nwcsvr5asrpayxx57tjzkj8ctf2cm77r\\\\\\\" amount:\\u003cdenom:\\\\\\\"stake\\\\\\\" amount:\\\\\\\"10\\\\\\\" \\u003e \\\" at position 0: 0stake is smaller than 10stake: insufficient funds\"",
          "index": true
        }

After, it looks like:

 {
          "key": "logs",
          "value": "\"proposal execution failed on proposal 2, because of error message /cosmos.bank.v1beta1.MsgSend at position 0: 0stake is smaller than 10stake: insufficient funds\"",
          "index": true
        }

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)