Edited field in the app mention event

This commit add edited field to the app mention event

Sometimes it is important to react on the mention only once. The field helps to distinguish whether the message is original or edited

https://github.com/slack-go/slack/issues/961

Example:

{
    "envelope_id": "********",
    "payload": {
        "token": "********",
        "team_id": "T********",
        "api_app_id": "A********",
        "event": {
            "client_msg_id": "********",
            "type": "app_mention",
            "text": "********",
            "user": "U********",
            "ts": "1706785424.099119",
            "blocks": [
                {
                    "type": "rich_text",
                    "block_id": "7Kvco",
                    "elements": [
                        {
                            "type": "rich_text_section",
                            "elements": [
                                {
                                    "type": "text",
                                    "text": "text"
                                }
                            ]
                        }
                    ]
                }
            ],
            "team": "T********",
            "edited": {
                "user": "U********",
                "ts": "1706785427.000000"
            },
            "thread_ts": "1706785424.099119",
            "reply_count": 1,
            "reply_users_count": 1,
            "latest_reply": "1706785424.915589",
            "reply_users": [
                "U********"
            ],
            "is_locked": false,
            "subscribed": false,
            "channel": "C********",
            "event_ts": "1706785424.099119"
        },
        "type": "event_callback",
        "event_id": "********",
        "event_time": 1706785424,
        "authorizations": [
            {
                "enterprise_id": null,
                "team_id": "T********",
                "user_id": "U********",
                "is_bot": true,
                "is_enterprise_install": false
            }
        ],
        "is_ext_shared_channel": false,
        "event_context": "********"
    },
    "type": "events_api",
    "accepts_response_payload": false,
    "retry_attempt": 0,
    "retry_reason": ""
}

slack-go / slack

Edited field in the app mention event #1256