Show preview of the filename in the save settings
Summary:
Shows the a preview of the configured filename template on the save settings page. I'm not sure about the placement of the label but the functionality should be there. This also again includes a small refactor to access the placeholder replacement from outside of the ExportManager.
BUG: 381175
Test Plan:
Reviewers: Spectacle, VDG, ngraham
Reviewed By: Spectacle, VDG, ngraham
Subscribers: meven, ngraham, broulik
Tags: Spectacle
Differential Revision: https://phabricator.kde.org/D19775