feat: adjust alert template title and body to reflect alert state - #1339

)

Currently, the resolved alert will have the same title and body message as the alerting one, which is misleading

Ref: HDX-2786

## Slack

### ALERT
<img width="723" height="358" alt="Screenshot 2025-11-09 at 10 02 52 PM" src="https://github.com/user-attachments/assets/b1c6f563-f095-457e-9a70-01c8149796c4" />

### RESOLVED
<img width="650" height="117" alt="Screenshot 2025-11-09 at 10 26 01 PM" src="https://github.com/user-attachments/assets/07ef1e7d-8ee5-4604-92cf-4811a0a5c811" />

## incident.io

### ALERT
<img width="1432" height="398" alt="Screenshot 2025-11-09 at 11 07 30 PM" src="https://github.com/user-attachments/assets/30e25eb3-32b2-4f51-934d-b28e75dd5cf7" />

### RESOLVED
<img width="1427" height="305" alt="Screenshot 2025-11-09 at 11 08 56 PM" src="https://github.com/user-attachments/assets/913a5b99-bb07-47ae-bec9-6b0814e4b400" />

#3467)

## Summary

Closes #3466

I know #3466 hasn't been through feedback yet and CONTRIBUTING asks for `Accepting PR` first. I had already written and tested this before filing the issue, so I'm opening it now in case it helps the discussion. Happy to rework it or close it if you want a different direction.

Alert notification titles always start with 🚨 or ✅. That reads well in Slack, but a destination that already says firing or resolved, such as a webhook feeding an email relay, gets the emoji in its subject line with no way to remove it.

Following review, this is now a setting on the webhook rather than the alert: an optional boolean `titleEmoji`, where `false` drops the prefix for notifications sent to that webhook. Unset or `true` leaves titles unchanged. An alert that notifies several webhooks through `@webhook-` mentions gets the prefix per destination.

- The title is built once without the emoji, and the prefix is added per channel when the dispatch jobs are queued, unless that webhook opts out.
- The field follows `description` through the webhook model, the internal and v2 webhook APIs, `openapi.json` and the common-utils types.
- The webhook form has a "Show state emoji in notification titles" checkbox, checked by default.
- The MCP `saveWebhook` tool takes the field, since its update clears omitted settings.

### How to reproduce

**Starting point:** `yarn dev`, with two webhook destinations and a saved-search alert that notifies both (one as its channel, one through an `@webhook-` mention in the message).

**On `main`:**

1. Trigger the alert. Both notification titles start with 🚨, and no setting removes it.

**On this branch:**

1. In Team Settings, edit the first webhook and untick "Show state emoji in notification titles".
2. Trigger the alert. The first webhook's title has no prefix, the second keeps 🚨, and the resolved notifications follow the same split.
3. `GET /api/v2/webhooks` returns `"titleEmoji": false` for the first webhook.

`make dev-int FILE=checkAlerts` runs the two-webhook case.

### How to test on Vercel preview

Open Team Settings, edit or create a webhook, and check that the new checkbox saves and reloads.

### References

- Linear Issue:
- Related PRs: #1339