fix: add periodic yield to save_new_files

[TheBobBobs]

Summary

Fixes #986

Replacing the add_entries call with a sleep(2.0) was still causing segfaults so this seems to be a Qt issue.
Adding a yield before every call to add_entries keeps Qt happy.

Tasks Completed

• Platforms Tested:
  • Windows x86
  • Windows ARM
  • macOS x86
  • macOS ARM
  • Linux x86
  • Linux ARM
• Tested For:
  • Basic functionality
  • PyInstaller executable

[CyanVoxel]

Due to #986 being difficult to reproduce on command, I'm unable to confirm if this fixes the issue. If anyone else is able to reproduce #986 reliably or can confirm that this fixes the issue for them, that would be greatly appreciated.

[TheBobBobs]

I was able to get a segfault 70% of the time on startup with these steps.

1. Backup ts_library.sqlite
2. Add a few 100 files to your library. (I just copied from .TagStudio/thumbs)
3. Start tagstudio and wait for page to update or segfault
4. Close and revert ts_library.sqlite
5. Repeat from 3

[CyanVoxel]

I was able to get a segfault 70% of the time on startup with these steps.

1. Backup ts_library.sqlite

2. Add a few 100 files to your library. (I just copied from .TagStudio/thumbs)

3. Start tagstudio and wait for page to update or segfault

4. Close and revert ts_library.sqlite

5. Repeat from 3

This is essentially what I've tried, but I've only ever been able to get to it segfault maybe 5% of the time in comparison

[TheBobBobs]

Replacing the call to add_entries with a time.sleep(2.0) might be more reliable. Also removes the need to revert to backup