Introduce AE measurements

What does this MR do and why?

Introduce 2 new base metrics (min and max) and AE measurements macro.

It can be used to introduce all common metrics for row-level measurement and group metrics logically.

Screenshots or screen recordings

 {
  organization(id: "gid://gitlab/Organizations::Organization/1") {
    analytics {
      agentPlatformSessions(descendantsScope: {
        groupFullPaths: "gitlab-org"}) {
        aggregated {
          nodes {
            duration {
              mean
              max
              min
              quantile(quantile: 0.9)
            }
          }
        }
      }
    }
  }
}

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Related to #609263