Require all commits in a MR to have a green pipeline before merging

Description

Some workflows require that all the commits in a merge request have an associated green pipeline, otherwise you are not allowed to merge. This implies that you also need a pipeline for each commit, not just the last in a specific push.

Proposal

1. Introduce a new option that will create a pipeline for every commit
2. Introduce a new option that will allow merging only if all the commits have a green pipeline

These two features are orthogonal, but strictly related because you probably don't require 2 if you are not using 1, so it can be a suboption instead of a separate one.