ui: recent libraries list improvements

[CyanVoxel]

Summary

This PR makes a couple tweaks to the Recent Libraries menu item:

1. Add a more specific error message when trying to open a library location that no longer exists (while keeping in mind that the full library path may not always be shown anymore, and in the future library files may not be in the same location as the folders they use)
2. Increase the recent library list limit from 5 to 10

Tasks Completed

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

[kitsumed]

I think this pull will also close : #810.
But I'm not sure 100% as the error message was saying access denied but this might be related to be file not beeing found / readable.

[CyanVoxel]

I think this pull will also close : #810. But I'm not sure 100%.

#810 seems unrelated as it's a different error in a different part of the codebase

[Computerdores]

Wouldn't it be better if it always showed the full path in the "Library Not Found" message? After all, knowing that a directory called "XYZ" wasn't found somewhere on the drive isn't all that useful (and not everyone is on top of their file organisation enough to immediately know where they had the library)

[CyanVoxel]

Wouldn't it be better if it always showed the full path in the "Library Not Found" message? After all, knowing that a directory called "XYZ" wasn't found somewhere on the drive isn't all that useful (and not everyone is on top of their file organisation enough to immediately know where they had the library)

I think it would, however with the setting introduced in #841 this may be considered a privacy concern for those who don't want their full file paths displayed on screen anywhere. Maybe that's just me reading into it too much though. After all, the About screen still shows the full config path location.

[Computerdores]

Besides me uncovering an unrelated bug (#889) while testing, this seems work perfectly!
(I still think that it would be good to have a setting in the future whether to show the full path in the popup, but this seems good as is)