[APM] API tests for creating alerts

[kpatticha]

related #152329
connected to: #79284

Fix

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1. refactor api test for alerts - [APM] Refactor alert test scenarios  #155985 scenarios
2. test empty params - cover the [APM] Add transaction name filter in failed transaction rate rule type #155405 (comment)
3. add test scenario for - [APM] APM rule types create incorrect alerts in some cases #94397
4. test transaction.name filter for duration threashold
5. test transaction.name filter for failed error rate threashold
6. test error.grouping.key filter
7. test the the edit flow. existing rule -> update -> add transaction filter ->
8. validate alert documents with the expected params
9. waitForAlertInIndex should accept the timerange

we should cover the following scenarios with API tests:

For each rule type, create a rule, and verify whether it fires and recovers appropriately, and fires the correct alerts, e.g. whether the grouping/thresholds etc are interpreted correctly. Query the alerts-as-data APIs/indices to verify whether that is the case.

[elasticmachine]

Pinging @elastic/apm-ui (Team:APM)