consider blacklist feature

[jixuan1989]

Hi, how about considering adding a new feature to screen someone?

In our project, IoTDB, we are using Sonar to check the code quality.
Then, for each PR (and for each update after a PR is opened),
the Sonar robot will leave a comment to say whether the PR has code quality problems.

We like the feature. But.... as some PRs have problems and the committer may update it many times, we receive a... message bomb...

So, if we have a blacklist feature, we can screen the message from a specific user (in many cases it is a robot).