shows warning dialog when exporting with metadata problems

Runs for #1630 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10%

• 1757dbf ✔ Run #77837267626 16s on webkit Merge branch 'main' into benchmark-relative-change by Gwenn Le Bihan 2 hours ago
• 1757dbf ✔ Run #77837267652 9s on chromium Merge branch 'main' into benchmark-relative-change by Gwenn Le Bihan 2 hours ago
• 92595fc ✔ Run #77775192688 10s on chromium Update playwright.yml by Gwenn Le Bihan 14 hours ago
• 92595fc ✔ Run #77775192703 20s on webkit Update playwright.yml by Gwenn Le Bihan 14 hours ago
• 7976a3e ✔ Run #77767467837 10s on chromium 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10% by Gwenn Le Bihan 15 hours ago
• 7976a3e ✔ Run #77767467803 16s on webkit 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10% by Gwenn Le Bihan 15 hours ago
• 5c4f919 ✔ Run #77733293888 10s on chromium 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10% by Gwenn Le Bihan 20 hours ago
• 5c4f919 ✔ Run #77733293770 16s on webkit 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10% by Gwenn Le Bihan 20 hours ago
• ea3b517 ✔ Run #77710933986 16s on webkit 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10% by Gwenn Le Bihan 23 hours ago
• ea3b517 ✔ Run #77710933912 10s on chromium 👩‍💻‍ Show benchmark changes in relative differences, consider no change if |<| 10% by Gwenn Le Bihan 23 hours ago