Mobile app cannot upload to folders who's names contain symbols

### ⚠️ Before posting ⚠️

- [x] This is a **bug**, not a question or an enhancement.
- [x] I've [searched for similar issues](https://github.com/nextcloud/android/issues) and didn't find a duplicate.
- [x] I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/).

### Steps to reproduce

1. Create a folder containing symbols (in my case I included `<3` in the name)
2. Try to upload a file to the folder
3. You will receive the error "Could not copy file to a temporary folder. Try to resend it"

### Expected behaviour

The folder creates and the file uploads

### Actual behaviour

The folder can be created, and uploaded to from the web app with no problems. However, on Android, you can create the folder, but it's not possible to upload files into it. You get an error pop up saying the temporary folder cannot be created, which im assuming is part of the internal upload process on the android client (making a temp folder and copying the files)

The reason for this is because certain characters are disallowed by Android https://cs.android.com/android/platform/superproject/+/master:frameworks/base/core/java/android/os/FileUtils.java;l=972?q=isValidFatFilenameChar
I think this could be fixed fairly easily by just making the folder name a UUID or a base64 encoded version of the name

### Android version

14

### Device brand and model

Samsung Galaxy S23 Ultra

### Stock or custom OS?

Stock

### Nextcloud android app version

3.31.0

### Nextcloud server version

31.0.1

### Using a reverse proxy?

No

### Android logs

_No response_

### Server error logs

```bash

```

### Additional information

_No response_