Add logic to Projects::AllBranchesRule::MergeRequestApprovalSetting to load prevent_committer_approval

Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.

• Close this issue

In Create Projects::BranchRules::MergeRequestAppro... (#504615 - closed) we created a new table and renamed some of the attributes to better suit the new system.

merge_requests_disable_committers_approval has been renamed to prevent_committer_approval so we need to create a method in Projects::AllBranchesRule::MergeRequestApprovalSetting to fetch project.merge_requests_disable_committers_approval