Collect instance names in the inventory and expose them as metrics labels

[demeringo]

Problem

It seems that the inventory only collects instances id's (and not their name).

Solution

It would be usefull add the name of the instances (or volumes ?) to the inventory and expose as metrics labels.

Alternatives

In the case of AWS, the instance name is maybe already present as a tag.

Additional context or elements

[jnioche]

Would these be coming from KeyName in the inventory?
I think it would also be useful to report metrics on InstanceType so that users are able to see the ones we are not getting data for from the API, see for instance Boavizta/boaviztapi#338