unquoteAndUnescapeNewlines

Removes enclosing double quotes from the string if present and replaces escaped newline characters ("\n") with actual newlines.

This method checks if the string starts and ends with double quotes. If true, it removes the leading and trailing double quotes. It then replaces all occurrences of the escaped newline sequence "\n" with actual newline characters.

Example:

The string:
`"Hello World!\n\n123"`

Will turn into:
`Hello World!

123`