Fix/QB-2411: Events optimization

[Xiong-stratos]

No description provided.

[BoThe1K]

This has been done because

func createEvents(events sdk.Events, msg sdk.Msg) sdk.Events {
	eventMsgName := sdk.MsgTypeURL(msg)
	msgEvent := sdk.NewEvent(sdk.EventTypeMessage, sdk.NewAttribute(sdk.AttributeKeyAction, eventMsgName))

	// we set the signer attribute as the sender
	if len(msg.GetSigners()) > 0 && !msg.GetSigners()[0].Empty() {
		msgEvent = msgEvent.AppendAttributes(sdk.NewAttribute(sdk.AttributeKeySender, msg.GetSigners()[0].String()))
	}

	// verify that events have no module attribute set
	if _, found := events.GetAttributes(sdk.AttributeKeyModule); !found {
		// here we assume that routes module name is the second element of the route
		// e.g. "cosmos.bank.v1beta1.MsgSend" => "bank"
		moduleName := strings.Split(eventMsgName, ".")
		if len(moduleName) > 1 {
			msgEvent = msgEvent.AppendAttributes(sdk.NewAttribute(sdk.AttributeKeyModule, moduleName[1]))
		}
	}

	return sdk.Events{msgEvent}.AppendEvents(events)
}

when event with module name occured, it will not stored for message.module rather then <module.name.Proto>.module so it is hard to search events through tx_search query

as example

with these removals:

{
"type": "message",
"attributes": [
{
"key": "action",
"value": "/cosmos.gov.v1beta1.MsgSubmitProposal",
"index": true
},
{
"key": "sender",
"value": "st1t9aw4w9tdv3ccj2p53nmta8axcueaewysgujd8",
"index": true
},
{
"key": "module",
"value": "gov",
"index": true
}
]
}

without (before PR)

{
"type": "stratos.pot.v1.EventMessage",
"attributes": [
{
"key": "action",
"value": "",
"index": true
},
{
"key": "module",
"value": "pot",
"index": true
},
{
"key": "sender",
"value": "st1eqmjp3vfknvzzd9zzkx5khkf68hzhwdcyd0n3s",
"index": true
}
]
}