crowdstrike: add more robust test cases for EppDetectionSummaryEvent events

[efd6]

#12869 added support for EppDetectionSummaryEvent events. However, a full set of test events were not available to add to testing before the deadline for making the feature available, so it was merged with a limited set of tests. This issue is to track adding a full set of tests for that event type.

Related parent issue for the feature is #12867.

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[cpascale43]

Will try to grab samples for this.

[cpascale43]

Samples shared in the linked ER.