Extend GitLab API to retrieve historical state changes of Epics

Release notes

Problem to solve

This feature aims to help any customer integrate GitLab with a product management tool that requires visibility over state changes of Epics.

Proposal

Expand the API capabilities to return the historical state changes of Epics.

This functionality can be currently implemented (workaround) on self-managed by querying the resource_state_events table, however, there is no interim solution for SaaS customers.

Intended users

Parker (Product Manager) Delaney (Development Team Lead) Sasha (Software Developer)

Feature Usage Metrics

Number of API calls customers are making