Rename "Master" to "Copy template"

Goal: Clearer naming to avoid editor confusion

Who: Editors


In German the two terms are "Lesezeichen" which is the bookmark and "Kopiervorlage" which at the moment is translated to "Master". Please change that to "Copy template" as that fits the usage better.

Why: More clear and specific wording

Bonus: Gets rid of a potentionally offensive term