Method of Deduplicating Metrics

Is your feature request related to a problem? Please describe.
We want to use the metrics system in Metabase but if you allow self service (which is the goal here) it's very easy for metrics to be duplicated (multiple metrics with the same names and multiple metrics with the same definition). We would have to build a process around 'who or what creates metrics' and 'when or where do we adjust / compare those.'

Describe the solution you'd like
On creation of a metric it would be nice if users were notified that a metric with the same definition and/or name already existed. It would also be great to have some centralized way to identify duplicate metric names and definitions that already exist.

Describe alternatives you've considered
Exporting the metrics somehow and tracking them in an external tool, like Airtable, for validation and deduplication.

Additional context
Customer request

The issue does not name any files, tests, or entry points. Start by locating the metrics creation and listing flows in the Metabase codebase, then clarify whether duplicate names, duplicate definitions, or both must be detected and how users should be notified. Done should include an agreed design for identifying existing duplicates and handling them during creation.