[BE] refactor: MockData 설정 로직 리팩터링 및 테스트 속도 개선 (#839) #753

All 661 tests pass in 24s

199 files ±0 199 suites ±0 24s ⏱️ ±0s
661 tests ±0 661 ✅ ±0 0 💤 ±0 0 ❌ ±0
674 runs ±0 674 ✅ ±0 0 💤 ±0 0 ❌ ±0

Results for commit 80c2514. ± Comparison against earlier commit eb75e63.