chore(announcements): sync changes from template

[dcshzj]

Problem

There are changes to the template that have not been synced to the CMS frontend: isomerpages/isomerpages-template#323

Solution

Breaking Changes

• Yes - this PR contains breaking changes
• No - this PR is backwards compatible with ALL of the following feature flags in this doc

Improvements:

• Changes to the announcements component preview are now synced with the changes made on the template.

Before & After Screenshots

BEFORE:

AFTER:

Tests

• Unit tests (using npm run tests)
• e2e tests (comment on this PR with the text !run e2e)
• Smoke tests
  • Navigate to any site's homepage that can use the new template components
  • Add a new announcements block
  • Verify that the size of the block is now the entire width (AFTER screenshot) instead of being compressed (BEFORE screenshot)

Deploy Notes

None