COPY file/folder to same name is possible (but 500 code error for folder with spaces path)

### Step to Reproduce
1. Create this folder tree:
- `parent/child/lorem.txt`
2. COPY `parent/child/lorem.txt` to `parent/child/lorem.txt`
```bash
curl -XCOPY "https://localhost:9200/remote.php/spaces//parent/child/lorem.txt" \
-H"Destination: https://localhost:9200/remote.php/spaces//parent/child/lorem.txt" \
-uadmin:admin -vk
```
4. COPY `parent/child` to `parent/child`
```bash
curl -XCOPY "https://localhost:9200/remote.php/spaces//parent/child" \
-H"Destination: https://localhost:9200/remote.php/spaces//parent/child" \
-uadmin:admin -vk
```

### FIndings
1. COPY to same file:
```
/webdav - 204 (file content exists)
/dav/files - 204 (file content exists)
/dav/spaces - 204 (file content exists)
```
2. COPY to same folder:
```
/webdav - 204 (folder exists but folder content is moved to trashbin - ❓)
/dav/files - 204 (folder exists but folder content is moved to trashbin - ❓)
/dav/spaces - 500 (not possible in dav/spaces path)
```
NOTE: With `Overwrite: F header`, all requests return `412 Precondition Failed`

### Queries
1. What is the actual behavior? Is it possible COPY to same path ?
2. Should copying folder into same path result in creating new folder while sending that folder to trashbin?