Add option to sort for original date

Summary:
Takes the original date a photo was taken out of the data provided by Baloo & makes it available to the user

FEATURE: 303645

{F5671033}

Test Plan:
- Works with a batch of time-tagged photos
- Can be hidden/shown/sorted like any other property

Reviewers: #dolphin, ngraham, elvisangelaccio

Reviewed By: #dolphin, ngraham, elvisangelaccio

Subscribers: elvisangelaccio, ngraham

Differential Revision: https://phabricator.kde.org/D10059