Rename approval rule “Name” field to “Rule name”

From gitlab-design#441 (closed).

This field can lead to some confusion: What do I have to fill in here? I can try the name of the person I want to add as approver, but nothing shows up, so this is probably wrong. The hint says QA or Security, so maybe I have to add groups here?

Suggestion: Rename “Name” field to “Rule name”.