Group:Source Code Evaluate feature tiers following buyer tier model

In #270 (closed), we discussed realigning our EE feature set with our buyer tier model.

buyer persona. Let's also remember that features can only be moved down in tiers, not up. Let's take features from features.yml.

Feature Current Tier Target Buyer Persona Proposed Action Issue URL
Optional Merge Request Approvals Starter Director/Manager Move to Core https://gitlab.com/gitlab-org/gitlab-ce/issues/59197 - optional approvals with no enforcement allow a formalized code review process where a merge request can be approved
Required Merge Request Approvals Starter Director/Manager - https://gitlab.com/gitlab-org/gitlab-ce/issues/42096
Merge Request Reviews Premium Director/Manager Move to Core https://gitlab.com/gitlab-org/gitlab-ce/issues/60690 - leaving comments in a batch reduces notification and noise and allows a code review to be paused and resumed. This great for usability but doesn't make the buyer tier Director/Manager level. This has also been requested by OSS project wanting to switch to GitLab.
Pull Mirroring Starter Director/Manager - https://gitlab.com/gitlab-org/gitlab-ce/issues/48981
Push Rules Premium Director/Manager - https://gitlab.com/gitlab-org/gitlab-ce/issues/25872
File locking Premium Director/Manager - -
Protected branches (users) Starter Director/Manager - -
Contribution Analytics Starter Director/Manager - -
File templates Premium Director/Manager - -
Merge Request Dependencies Premium Director/Manager - -
Multiple Merge Request Assignees Starter Director/Manager - -
Edited by James Ramsay (ex-GitLab)