SREs can silence an alert and link it to an issue with one command

This command might make most sense as a button on Slackline V2 alerts (https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/10871). We already have helicopter, which labels and comments on issues corresponding to silences.

Think holistically about what the ideal relationship between SREs, GitLab project planning, and silences is, and propose a plan here.