Fixed or recovered pipeline emails notification

For now there's only successful pipeline emails or failed pipeline emails. However usually we don't care about all successful pipelines, we only care if it's recovered from a broken state, or perhaps if it's the first successful pipeline.

In other words, only send successful pipeline emails whenever it meets:

• The first successful pipeline for a new branch
• If last pipeline from the same branch was failed, current successful pipeline is the "fixed" or "recovered" pipeline. Notify this one.
• All successful pipelines for tags

Other pipelines to consider:

• Triggered from API
• Created from web UI

Related issues: #24635 (closed), #24845 (closed), #24892 (closed), #25028 (closed)

/cc @ayufan @markpundsack