Bug report: Copy paste from MynahUI should not contain unnecessary line breaks

[leigaol]

Problem

This is a mirror of issue https://github.com/aws/aws-toolkit-vscode/issues/4991.

Steps to reproduce the issue

Resize chat window, then copy from chat window. The copied text contains line breaks that were added by MynahUI which does not exists in the original string.

Expected behavior

System details

• OS:
• Tested enviroment:
  • [x] Web (Demo app)
  • [x] VSCode Amazon Q Chat
  • [x] JetBrains IntelliJ Amazon Q Chat
• Enviroment extension version (if applicable):
• [-] Enviroment is remote