Performance significantly degrades when uploading or scanning directories with a large number of files

### ⚠️ 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. Put over 10'000 photos in a directory, if possible on a SD card
2. Enable upload of existing files of this directory in Nextcloud

### Expected behaviour

Nextcloud android client should be response fast, especially the upload page

### Actual behaviour

Nextcloud becomes very slow, especially the upload tool is not usable

Android shows often the message that the app does not respond

Also detecting additional files takes much time

### Android version

14

### Device brand and model

Fairphone 4

### Stock or custom OS?

Stock

### Nextcloud android app version

3.32.2

### Nextcloud server version

31.0.7

### Using a reverse proxy?

No

### Android logs

_No response_

### Server error logs

```bash

```

### Additional information

_No response_