Text nodes were decoded without line-end normalisation, so a file
saved with Windows line ends kept the CR of each CR LF: a line break
inside w:t read as two spaces. Text and CDATA now go through
quick-xml's xml_content, which reads CR LF and a lone CR as one line
feed; a CR written as stays a CR. Attribute values were already
normalised.
Co-authored-by: Martin Ball <martin.ball@ucscaregroup.co.uk>