Add support new memberships

[stevencrader]

Detect and report new membership.

Example message:

{
    "data": {
        "messages": [
            {
                "blocks": [
                    {
                        "data": {
                            "text": "Defected is my ABSOLUTE favorite show! I watch several of them AND read all of the Badlanders on SubStack, but you two are the best!"
                        },
                        "type": "text.1"
                    }
                ],
                "id": "961986094364777049",
                "notification": {
                    "badge": "recurring_subscription",
                    "text": "is now a monthly supporter!"
                },
                "rant": {
                    "duration": 300,
                    "expires_on": "2023-04-03T02:35:56+00:00",
                    "price_cents": 500
                },
                "text": "Defected is my ABSOLUTE favorite show! I watch several of them AND read all of the Badlanders on SubStack, but you two are the best!",
                "time": "2023-04-03T02:30:56+00:00",
                "user_id": "17316865"
            }
        ],
        "users": [
            {
                "badges": [
                    "recurring_subscription",
                    "whale-gray"
                ],
                "color": "#ed5b47",
                "id": "17316865",
                "username": "LLSummers"
            }
        ]
    },
    "request_id": "UR2u8B5LkhmGWLyhMfmxC1F6CgD6jz5wFpk39l6iB8g",
    "type": "messages"
}