[ES|QL] Enhance the recommended queries with the event rate option (e…

…lastic#196803)

## Summary

Adding another option to the recommended queries templates

<img width="1905" alt="image"
src="https://github.com/user-attachments/assets/e4def9bc-7d96-449f-a81f-c53d697ac38f">

packages/kbn-esql-validation-autocomplete/src/autocomplete/recommended_queries/templates.ts

@@ -100,6 +100,21 @@ export const getRecommendedQueries = ({
             ),
             queryString: `${fromCommand}\n  | WHERE ${timeField} <=?_tend and ${timeField} >?_tstart\n  | STATS count = COUNT(*) BY \`Over time\` = BUCKET(${timeField}, 50, ?_tstart, ?_tend) // ?_tstart and ?_tend take the values of the time picker`,
           },
+          {
+            label: i18n.translate(
+              'kbn-esql-validation-autocomplete.recommendedQueries.eventRate.label',
+              {
+                defaultMessage: 'Calculate the event rate',
+              }
+            ),
+            description: i18n.translate(
+              'kbn-esql-validation-autocomplete.recommendedQueries.eventRate.description',
+              {
+                defaultMessage: 'Event rate over time',
+              }
+            ),
+            queryString: `${fromCommand}\n  | STATS count = COUNT(*), min_timestamp = MIN(${timeField}) // MIN(dateField) finds the earliest timestamp in the dataset.\n  | EVAL event_rate = count / DATE_DIFF("seconds", min_timestamp, NOW()) // Calculates the event rate by dividing the total count of events by the time difference (in seconds) between the earliest event and the current time.\n | KEEP event_rate`,
+          },
           {
             label: i18n.translate(
               'kbn-esql-validation-autocomplete.recommendedQueries.lastHour.label',