Migrate epic events to snowplow vol. 6 - epic links events

What does this MR do and why?

Related to #366827 (closed)

Migrate some of the redis_hll_counters.ecosystem.ecosystem_total_unique_counts_monthly event's sub-events to Snowplow.

Screenshots or screen recordings

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How to set up and validate locally

1. Enable snowplow micro
2. Setup a Jira integration: create a free Jira cloud account and configure it in gitlab as described here
3. Trigger any of the events migrated here:

• enter the jira issue list view [http://127.0.0.1:3000/your_group/your_project/-/integrations/jira/issues]
• in the Jira integration's settings, make sure that creating an issue from a vulnerability is enabled. Then, go to security -> vulnerability, enter a single vulnerability view and click the "create Jira issue" button and create the issue in Jira.

3. Check if a new event with perform_integrations_action action and se_property attribute describing the performed action has been registered at localhost:9090/micro/good

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.