Refactor event store to use migration mechanism #7373

All 1 397 tests pass in 10m 25s

4 files ±0 55 suites ±0 10m 25s ⏱️ +5s
1 397 tests ±0 1 397 ✅ ±0 0 💤 ±0 0 ❌ ±0
1 611 runs ±0 1 611 ✅ ±0 0 💤 ±0 0 ❌ ±0

Results for commit 9a7bf92. ± Comparison against earlier commit 978854d.