Issue alert slack messages to update initial message on resolution/archiving

### Problem Statement I have Sentry issue alerts set up in my project, that post to Slack. I have them configured at a relatively sensitive threshold, so I receive alerts for many issues. Furthermore, I have a process where I want the oncall engineer to acknowledge every alert, by doing one of the following: 1. Land a fix / suppression in the code, and mark the issue as Resolved 2. "Snooze" the issue by Archiving it for some time / until it hits a volume threshold If they do not take one of these actions, the alert will retrigger the next day (action interval 24h), sending a new slack message. In this model, it is difficult to see, when scrolling the slack channel, the state of those alerts. Furthermore, the Sentry UI is not helpful for going down the set of "issues firing alerts". It can show archived & resolved issues, but not whether they were firing alerts recently for example. The fact that Sentry posts future firings into a thread instead of the channel directly is great. When you resolve or archive an issue, Sentry does post an update into the thread with the information: "Jordi Paris Ferrer marked as resolved in an upcoming release" which is also great. However, these do not let you get a sense from the channel itself the state of those issues & alerts without a few clicks into Sentry. ### Solution Brainstorm Extend the slack thread message to also edit the top-level message, or ideally every message in the thread. Maybe changing the color, adding some strike outs, etc to make it clear that the issue that triggered the alert has been actioned within Sentry. For example, the Pagerduty slack integration will update their message with acked, resolved states: <img src="https://github.com/user-attachments/assets/9595b4dd-a420-4b32-9857-26aab57ece4a " alt="Image" width="1242" data-linear-height="484" /> ### Product Area Alerts We want to define a set of [lightweight metrics](<https://docs.sentry.io/product/explore/metrics/>) that SDKs can automatically collect for…