In plugins, we are using non consistent naming. We use `elasticsearch-cloud-aws` as the artifactId, which generates a jar file called `elasticsearch-cloud-aws-VERSION.jar`.
But when you want to install the plugin, you will end up with a shorter name for the plugin `cloud-aws`.
```
bin/plugin install cloud-aws
```
This commit changes that and use consistent names for `artifactId`, so `finalName`.
Also changed maven names.
This is one of our esoteric metadata mappers so I think we should distribute
it in a plugin rather than in elasticsearch core.
This introduces one limitation: the value of the `_size` parameter is not
retrievable for documents that are only in the transaction log.