Saccades across files

[Joshua2000B]

Per our discussion, saccades that occur across the transition of files should be categorized not as saccades but as IDE navigations. We will still be saving these as a saccade in the database, but they will have a different category.

There are a couple scenarios where these can occur.

1. The user automatically switches the file without moving their eye position (i.e., key combo to switch)
2. The user gazes at the project explorer, switches files, then gazes back (need to save other contexts as different gaze targets)
3. The user has two (or more) files open simultaneously and gazes between them without changing the stimuli