feat(design): add accessibility considerations to the notification component

[xelaint]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/graycoreio/daffodil/blob/develop/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Notification's accessibility considerations are not comprehensive enough.

Fixes: #2891

What is the new behavior?

1. warn and danger statuses have a role="alert"
2. notifications with actions also have a role="alert"
3. all other notifications (i.e. default (no status), success status) have a role="status"

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information