Support extended attributes

### Summary

Add support for extended attributes to store additional information for a file.

### Please agree to the following

- [x] I have searched [existing issues](https://github.com/cryptomator/cryptomator/issues?q=) for duplicates
- [x] I agree to follow this project's [Code of Conduct](https://github.com/cryptomator/cryptomator/blob/develop/.github/CODE_OF_CONDUCT.md)

### Motivation

Extended attributes are used to store more information about a file: A user given tag, the location of a photo taken, a second name etc.

Especially on macOS the extended attributes are used a lot (also from the filesystem, e.g. https://en.wikipedia.org/wiki/Resource_fork#Accessing).

### Considered Alternatives

_No response_

### Anything else?

Relates to #1523, #3974.

Currently, on macOS a volume is mounted with the `-noappledouble` or `-nonamedattr` flag, which prevent the usage of extended attributes.