Rename ImageMake and ImageModel properties

Summary:
Provide a more generic and meaningful property
and display name for the previous ImageMake and
ImageModel properties.

CCBUG: 343273

Reviewers: ngraham, bruns

Reviewed By: ngraham

Subscribers: kde-frameworks-devel, #baloo

Tags: #frameworks, #baloo

Differential Revision: https://phabricator.kde.org/D21519