Revamp admin/emails UI and add trigger buttons with Storybook references

[codemist]

References:

Jira: MNTOR-5269

This PR updates the /admin/emails route by adding trigger buttons for the new breach alerts variants and revamping the overall styling/UI for better usability and consistency. I also added Storybook story links within each card to make it easier to preview and validate email templates.

Description

Screenshot (if applicable)

Not applicable.

How to test

Checklist (Definition of Done)

• Localization strings (if needed) have been added.
• Commits in this PR are minimal and have descriptive commit messages.
• I've added or updated the relevant sections in readme and/or code comments
• I've added a unit test to test for potential regressions of this bug.
• If this PR implements a feature flag or experimentation, I've checked that it still works with the flag both on, and with the flag off.
• If this PR implements a feature flag or experimentation, the Ship Behind Feature Flag status in Jira has been set
• Product Owner accepted the User Story (demo of functionality completed) or waived the privilege.
• All acceptance criteria are met.
• Jira ticket has been updated (if needed) to match changes made during the development process.
• Jira ticket has been updated (if needed) with suggestions for QA when this PR is deployed to stage.

[Vinnl]

Just a drive-by comment to say that that screenshot looks neat, thanks!