[multi-part] Eliminate 1k selection limit

* Rename class ClipDetails.
* Add FileOperation class and merge it with JobFactory.

Bug: 28194201
Change-Id: I46639b21c9e424644289a1bf34b85234a9becd2b
(cherry picked from commit 7f17819f1320d12f1f35a8f5327e0c7e63dfed54)
25 files changed