feat(sqllab): Popup notification when download data can exceed row count

[justinpark]

SUMMARY

When user clicks "download to CSV" we would like to add a warning that there may actually be more data, so you aren't downloading the full data.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

https://github.com/user-attachments/assets/5c4d2ccf-3409-4818-9b9d-1fac0ff02801

TESTING INSTRUCTIONS

Set limit 10,000 and then run a query that may contain more than 10k.

ADDITIONAL INFORMATION

• [ ] Has associated issue:
• [ ] Required feature flags:
• [x] Changes UI
• [ ] Includes DB Migration (follow approval process in SIP-59)
  • [ ] Migration is atomic, supports rollback & is backwards-compatible
  • [ ] Confirm DB migration upgrade and downgrade tested
  • [ ] Runtime estimates and downtime expectations provided
• [ ] Introduces new feature or API
• [ ] Removes existing feature or API