Send target name parameter in cloud cache calls

[danieleformichelli]

We would like to add some metrics to our cloud cache backend, for example to have more insights on which artifacts are missing from the cache more often than others, or similar analysis.

To do that, we would like to add the target name as an optional target parameter to the exists/get/post calls to the cloud backend, in order to be able to pair an hash with a target. The parameter can be ignored by the backends that are not interested in it (as they already do for the projectID).

Do you see any problem with that? 🙌

[pepicrft]

As mentioned in Slack, when extending the cloud functionality it's important that we don't couple the client-side implementations to any specific backend. Because the target name is additional context, I'm onboard with the idea.

[danieleformichelli]

Opened a PR here