Rename vault without renaming folder

### 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

Rename vault without renaming folder

### Motivation

On the desktop version, it's possible to rename the vault without renaming the folder. I'd like this feature on iOS.

On the iOS version, renaming the vault also renames the folder. To me, this is more of a "move" (in the UNIX sense at least).

An example use-case would be to have the folder called "Cryptomator" (or whatever the users chooses) inside the cloud, to make it clear that it's for Cryptomator, but then inside Cryptomator have it called something else to make it clear what vault it is, like "Dropbox", "My Documents" or whatever the user chooses.

Otherwise, I'm forced to have long, redundant folder names just to distinguish my Cryptomator vaults in the app (different cloud providers).

### Considered Alternatives

_No response_

### Anything else?

I'd suggest renaming the current "Rename" to "Rename Folder", and add "Rename Vault" as option.

Start by tracing the iOS Rename action described in the issue and determine where the vault's displayed name is coupled to its folder name. Compare the existing behavior with the requested desktop behavior, then verify that renaming the vault leaves the folder unchanged while the current folder-renaming behavior remains available.

Written by the indexing model from the issue text.