[Bug Report] Non-ASCII performers fail to be tagged

[Still34]

Describe the bug
Non-ASCII performers appear to invalid to the auto taggers and cause the tagger to ignore the paths - specifically Japanese/Chinese in my case. Other non-ASCII characters were not tested.

To Reproduce
Steps to reproduce the behavior:

1. Create a directory containing non-ASCII character of the performer's name and move a valid media file to the directory.
2. Create a new performer with the non-ASCII character (e.g., 伏字).
3. Enqueue auto-tagging tasks.

Expected behavior
The media within the performer's directory should be tagged with the performer's metadata, but it is not.
e.g., /media/伏字/hello-world.mp4 should be tagged with the performer 伏字 that was just created.

Stash Version: (from Settings -> About):
v0.12.0-40-gc857e301

Desktop (please complete the following information):

• OS: Both Windows and Linux

[WithoutPants]

Reopening with a known issue that names with single unicode letters will not match due to a performance optimisation.