Enhancement: Split notification per Webhook in multiple calls

Hey everybody :)

Right now we're using the Webhook receiver to send alerts to Slack (because the native Slack receiver doesn't support the Slack BlockKit API yet). The problem is: With the new BlockKit API there is a limit of 50 blocks per Webhook call. Depending on your notification template you hit that limit rather fast (for us it's at 11 alerts).

Fortunately the Webhook receiver offers the possibility of capping / truncating the max number of alerts processed. That way we at least don't run into a Slack API error.

Unfortunately the truncated alerts are dropped and not further processed.

So my enhancement proposal would be to put the truncated messaged into a n subsequent webhook calls, so that they're not lost.

What do you think about that?