Some additional attributes are not visible in KeePassDX

### Checks

- [x] I have read the Wiki, searched the open issues, and still think this is a new bug.

### Explain the problem clearly and succinctly:

I use KeePassXC on PC, and in some entries, I have created an additional attribute named "Username". Those attributes are not visible in KeePassDX, I assume, because the default "Username" attribute already exists. It's visible on KeePassXC, though.

Personally, I consider this a bug, although some may disagree.

### Describe what you expected to happen:

_No response_

### KeePassDX version:

4.3.2

### Build:

Free

### Database version:

4.1

### File provider (`content://` URI)

_No response_

### Android version:

_No response_

### Android device:

_No response_

### Additional context:

_No response_

The issue names no source file or test. First reproduce the problem by opening a KeePassXC entry with an additional attribute named "Username" in KeePassDX 4.3.2, then trace the entry-attribute display path; done means the additional attribute is visible separately from the default Username field.

Written by the indexing model from the issue text.