Implement GOOD notifications to Mattermost channel

This template is ONLY used for feature requests. Bug reporting or pipeline enhancement issues should use the other template options for issue submission.

Description

This room was useful when we had Jenkins. Josh told us to re-implement it, but make it good this time. His recommendation would be to potentially notify on new CVEs. https://chat.il2.dsop.io/platform-one/channels/topic---cht-pipeline-notifications

Purpose

Plan

Possible Blockers/Challenges

Acceptance Criteria