When a file was added to the project since previous analysis (doesn't mean the file is new, could be because an exclusion was removed), issues should be backdated.
Choosing the date:
- For file-level issues (E.G. Files should not have too many lines), we will use the newest line in the file.
- Directory- and project-level issues - keep analysis date.
- In all other cases based on the newest line in the issue's location set.