feat(email-service): add suppression list tab and domain management UI with new API

[ornokreans]

Summary

feat(email-service): add suppression list tab and domain management UI

Changes Made

• Restored Suppression List tab (was hidden pending API, now visible)
• Restored Add Domain button in Email Identity Domains
• Restored trash icon (Remove) button per domain row

Checklist

• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have made corresponding changes to the documentation (if applicable).
• My changes generate no new warnings or errors.

[ornokreans]

This PR is waiting for the corresponding API to be done. Will be handed over to other colleagues to continue.