Post link for pipeline errors in a comment, if pipelines fail

[alalazo]

Many times occasional users struggle to find pipeline failures in PRs. Reviewers have to check the PR, look at the failure in pipelines, then manually post a comment with some link - to explain why the PR is still in the queue.

If we could post a message in the PRs with link to failures, similar to:

There are errors in <link to pipelines>:

<details>

<summary>Failed builds</summary>

- link 1 
- link 2
...

</details>

that would help users proceed independently with their PRs.