Synology Drive support

### 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

Support for Synology Drive cryptomator usage

### Motivation

People who doesn't trust online clouds and buys and build own server instead (e.g.: Synology NAS), can use Synology Drive to sync his data between devices in a secure way. It would be ideal to have another level security with cryptomator.

### Considered Alternatives

Tried many other apps and other ways, but not found one.

### Anything else?

_No response_