[multi-part] Eliminate 1k selection limit

* Remove clearing clip files at app launch.
* Remove clip files when they won't be used.
* Stop adding clip items to jumbo clip data.
* Repurpose ClipDetails to hold operation type, srcParent and file list.
* Use ClipDetails for copyTo/moveTo/delete menu actions.
* Make FileOperationService consume ClipDetails.
* Add set up state to jobs; show set up notification in set up phase.
* Make copy job cancelable at set up phase.

Bug: 28194201
Change-Id: I2018ff9bc51515c1f6a029f0ede3f4c7d2beee43