Aggregate counts for deployments

Problem

Currently, we are only counting deployments based on the existence of environments.

This undercounts how often people are actually using GitLab for deployments.

Proposal

Now that we have created a ci_user_executing_deployment_job counter, we would like to implement a new counter that aggregates (and deduplicates) ci_user_executing_deployment_job with the existing deployment MAU counter to create a new counter that represents total count of unique users (by deduplicated user_id) that made a deployment. Timeframes should be last 28d and all-time.

Previous Proposal

Once we create two counters that counts the stage and jobs with relevant names to deployments (not a perfect count), we will implement a new counter that aggregates the total count of unique users that made a deployment.

Out of scope

Originally, we wanted to create a new SMAU for ~"devops::release" based on the combination of deployments and release. The new SMAU should be based on the aggregate counter created in this issue, and the Release AMAU.