Display number of migration log warnings encountered after a migration completes #3723

All 782 tests pass in 26s

782 tests - 1 782 ✔️ - 1 26s ⏱️ -1s
    1 suites ±0     0 💤 ±0
    1 files ±0     0 ❌ ±0

Results for commit bba1c1a. ± Comparison against earlier commit 4a13cf2.