wsd: support line-breaks in watermark text

New-line breaks can now be inserted in the watermark
text using
. This helps break long watermark texts
at desired points and therefore make watermarks more
readable.

Change-Id: Ifee6faa06c9fb1fac38e5a4036c2e225829d796d
Signed-off-by: Ashod Nakashian <ashod.nakashian@collabora.co.uk>

kit/Watermark.hpp

@@ -22,7 +22,7 @@ class Watermark final
     Watermark(const std::shared_ptr<lok::Document>& loKitDoc, const std::string& text,
               double opacity)
         : _loKitDoc(loKitDoc)
-        , _text(text)
+        , _text(Util::replace(text, "\\n", "\n"))
         , _font("Carlito")
         , _alphaLevel(opacity)
         , _width(0)