Add support for SMB mounts

### Please agree to the following

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

### Summary

Add support for SMB locations within Cryptomator

### Motivation

Currently, the only way of mounting vaults on SMB locations is through the Files app, through the File Provider mechanism. Unfortunately, this method is extremely unstable and straight up does not work on iOS 16 (see issues #262 and #265). In addition, if the underlying SMB mount goes away (which happens often, because iOS/macOS automatically unmounts network shares if the network experiences any kind of fault), Cryptomator breaks down in unexpected ways (see issue #185).

Mounting directly within Cryptomator will cut out the middleware and *possibly* make the process more stable. At least the implementation won't go through the buggy File Provider.

### Considered Alternatives

Mounting through the file provider is an option, as stated above, but it isn't really an option, as demonstrated above with the various bug reports regarding SMB mounts.

### Anything else?

_No response_