$__interval calculation in alerting differs from dashboard&explore

short version: alerting sends the configured `min interval` value as the `.intervalMs` json-field, which becomes the `backend.DataQuery.Interval` value. this is not correct, because this means this is the `interval`, not `min interval`, so either the description is incorrect in the user-interface, or the calculation. long version: a comparison with dashboards: when `$__interval` is calculated in alerting, the result is different compared to dashboards&explore. when the $__interval (and it's friend `$__interval_ms`) is calculated in grafana dashboards/explore, (roughly) the following equation is used: `interval := max(time_range / max_data_points, min_interval)` so, if i set: `max_data_points := 10 ; time_range := "last-10-minutes"; min_interval := 5s`, then the `interval` will become `1m`. see this screenshot from dashboards, illustrating this: <img width="473" alt="dashboard" src="https://github.com/grafana/grafana/assets/51989/14f6c503-f29d-4d4e-bc90-6abaf275ddf5"> (and if i check in a datasource's `QueryData` method, the value arriving in `backend.DataQuery.Interval` is indeed `1 minute`) if i do the same in alerting, (see the attached screenshot), `backend.DataQuery.Interval` receives `5 seconds`. <img width="365" alt="alerting" src="https://github.com/grafana/grafana/assets/51989/dfef2aa9-62d7-4fe0-8762-6269a7869104"> it seems alerting sends the configured `min interval` value as the `.intervalMs` json-field, which, later, becomes `backend.DataQuery.Interval`.