Return effective trim point LSN on successful trim request #7989

All 46 tests pass, 1 skipped in 4m 19s

7 files ±0 7 suites ±0 4m 19s ⏱️ -14s
47 tests ±0 46 ✅ ±0 1 💤 ±0 0 ❌ ±0
182 runs ±0 179 ✅ ±0 3 💤 ±0 0 ❌ ±0

Results for commit d55eee4. ± Comparison against earlier commit 97beb75.