Describe the bug
Based on the docs, extraProperties should be included in file metadata (and also be loaded at import),

To Reproduce
Steps to reproduce the behavior:

1. Add tags and extraProperties to a file
2. Export to metadata
3. Clear tags from file
4. Import from metadata again

Expected behavior
extraProperties should again be visible after import.

Allusion version
latest

Desktop OS
Linux Mint

Additional context
Checking the metadata after writing to file using Online-Metadata does not show the extraProperties.