Shorten scan titles and usernames in scan requests

[stitch]

When names are too long in #451, scans in the API receive a 500. The longest name back then was used as an inspiration for limits on the API.

Shorten tracking info.

[stitch]

Shortened name of list from 80 to 20, shortened account name from 50 to 20. This means id's can grow extremely large and requesting scans will still work.