* Replace Prefire with a very similar but simpler and more direct approach
* Move PreviewTest snapshots to their new location (snapshotting default, mirrors UITests)
* Update acknowledgements
* Switch snapshot configuration extensions to a custom version
* Exclude snapshots from the PreviewTests target
* Fix acknowledgements
* Rename snapshotting preference keys
* Remove `skipPackagePluginValidation`
* Add the networkMonitor to the NSE and delete the old MockMediaLoader
* Generate a MediaLoaderMock through AutoMockable and use it in the MediaProviderTests
* Implement an ImageProvider mechanism that automatically tries reloading images when connectivity is established again and use it for LoadableImages
* Merge the ImageProvider protocol back into the MediaProvider
* Address PR review comments
* Provide a default sdk client request configuration
* Address tasks not automatically cancelling themselves when views get deallocated
