Improved review flow

Description

In our team, we are using only Gitlab for code reviews and we need to take some shortcuts during our process.

Existing process:

1. Merge request is submitted
2. Reviewers are adding comments
3. Developer resolves them and gets back to reviewers
4. Reviewers are accepting MR
5. Developer merges his MR.

We have troubles with during-review process. We could really use some buttons like "I'm reviewing" and "I reviewed" and "I made changes". We can do this with assignee but there can be only one assignee and we need two reviewers to accept MR. We could also use labels, and treat resolving comments as "I made changes" button but it's not enough.

Proposal

I have no real proposal. I could propose some changes (like buttons mentioned above) but I think there is a lot of people with different review flows and the review system should be more generic than just my team's flow.

I saw some discussions about rethinking review flow but they didn't seem to end with some conclusion.

Links / references

I think Gerrit is good example of review flow: https://www.gerritcodereview.com/ I am not asking to copy its functionality but this is one way of solving issues I mentioned.