Multicursor copy/paste not working as expected

### Apache NetBeans version

Apache NetBeans 19

### What happened

When copy/pasting with multi cursor selection "\n" is added to the pasted text

[Capture vidéo du 2023-10-03 21-28-21.webm](https://github.com/apache/netbeans/assets/35330562/7053a78e-a34d-44be-8ca2-d6f5aeacb86a)

### How to reproduce

Select two values
Copy
Paste to multicusror

Values pasted with \n character

### Did this work correctly in an earlier version?

Apache NetBeans 13 or earlier

### Operating System

Linux/Windows

### JDK

Any

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

Very frequently

### Are you willing to submit a pull request?

No

Start by reproducing the issue in Apache NetBeans 19 with two selected values, copy, and paste into a multicursor selection on Linux or Windows. Trace the editor's multicursor copy/paste handling and verify that pasted values no longer gain an added newline, then add a regression test if the relevant test area is identified.

Written by the indexing model from the issue text.