[Feature Request] Add SQLite DB to for downloaded file tracking

[bransoned]

Is your feature request related to a problem? Please describe.
If script crashes, no way to pick up where it left off. Would have to restart from the beginning, which would prove costly for large exports.

Describe the solution you'd like
Introduce a SQLite database to track files that have already been downloaded (either by their date/time string or their SID provided by Snapchat). Once a file has been downloaded, then catalog it into the database. This would also allow users to run this script every week or month to aggregate new memories without needing to re-import old images.

[bransoned]

Want to use the DB implementation to track files and their download/metadata status. Think this will be faster than using the Path.exists() function along with allowing future concurrent download implementation.