Improve Cosmos events

[NicolasMahe]

Improve the cosmos events by using a standard way but applicable to each module.

Currently, the mesg's events are hard to "query" because they use to much the cosmos sdk attributes:

ctx.EventManager().EmitEvent(
	sdk.NewEvent(
		sdk.EventTypeMessage,
		sdk.NewAttribute(sdk.AttributeKeyModule, types.AttributeValueCategory),
		sdk.NewAttribute(sdk.AttributeKeyAction, types.EventTypeCreateRunner),
		sdk.NewAttribute(sdk.AttributeKeySender, msg.Address.String()),
		sdk.NewAttribute(types.AttributeHash, runner.Hash.String()),
	),
)

related to #1639

[NicolasMahe]

@antho1404 we spoke about this somewhere, but I cannot find it. Do you know where?

[antho1404]

I don't see much things on github, there is a start of discussion here #1626 (comment)

I think we had this discussion mostly offline

[antho1404]

For the events we need a few things:

• An easy way to identify this type of event (I will call namespace)
• Enough data to know what's the event is about.

For the data, I would recommend having all the information

• resource: type of resource related to this event eg: service, process, execution...
• action: type of action on this resource eg: create, update, delete...
• hash: id of the resource

For the way to identify the event, we need to remove the use of the namespace from cosmos ("message") this is a cosmos namespace and makes it really complicated to filter.

Something that would be nice is to prefix the namespace with mesg to avoid conflicts first then put the resource and action.

mesg:execution:create [{ key: "hash", value: "xxxx" }, { key: "action", value: "create" }, { key: "resource", value: "execution" }]

This way we will be able to query all resources that has been created/updated and we can always query multiple resources with AND in the query. https://docs.tendermint.com/master/rpc/#/Websocket/subscribe

This would be ideal as we will have all the possibility and we can probably do some queries like
mesg:*:create (with CONTAINS "mesg:" AND CONTAINS ":create") to have all the creation of resources for example

If we are not too picky on the disk space we could actually broadcast the same event on all the different namespaces so it will be easier to query and have all information.

mesg                  [{ key: "hash", value: "xxxx" }, { key: "action", value: "create" }, { key: "resource", value: "execution" }]
mesg:execution        [{ key: "hash", value: "xxxx" }, { key: "action", value: "create" }, { key: "resource", value: "execution" }]
mesg:execution:create [{ key: "hash", value: "xxxx" }, { key: "action", value: "create" }, { key: "resource", value: "execution" }]