Add validation message as multiple lines

Summary:

Hi Team ,

I have a scenario where validation executes on few custom object fields upon custom button click.

The validation block has various checks and finally it should combine all error messages and show in single error popup as separate lines.

I have tried to achieve this but somehow the messages appear in single line ignoring new line character.

Any idea ?

TIA

Content (required):

As a user , I should be able to print validation messages line by line in a error popup.

Version (include the version you are using, if applicable):

23B

Code Snippet (add any code snippets that support your topic, if applicable):