Export list with name of decrypted files

### Please agree to the following

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

### Summary

Export list with name of decrypted files in a txt to find out in which vault it is located.

### Motivation

With so many vaults it becomes a little complicated to find out where a particular file is located, by allowing you to export a list with the name of the files the user would know in advance in which vault such file is located, thus avoiding having to open several vaults.

### Considered Alternatives

_No response_

### Anything else?

_No response_