refactor: update notification schema types

[Prithpal-Sooriya]

Explanation

This is just a helpful guide for Notifications team to update types to support the newly generated open api schema

References

Changelog

@metamask/package-a

• : Your change here
• : Your change here

@metamask/package-b

• : Your change here
• : Your change here

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've highlighted breaking changes using the "BREAKING" category above as appropriate
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes