_stbt.core: Refactor: Rename _AnnotatedTemplate => _ImageFromUser
_stbt.core: Refactor: Rename _AnnotatedTemplate => _ImageFromUser

I want to use this for mask images too, not just template images.

stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester