fix: Windows newline shows invalid character in text render (#4501)

Newline in strings on Windows is encoded as '\r\n', that is currently
not handled by the text render code and so carriage return (\r) shows up
in the rendered text. As a fix we simply ignore this character.
We came across this issue while exporting user specified text from DCCs
to render on Windows.

I'm not sure how to make a proper test case for this. Current tests
specify a command as a string that is passed to oiiotool as arguments
and executed in the command line. But adding a newline to the text
breaks the command.

Signed-off-by: Peter Horvath <peter.horvath@autodesk.com>
Signed-off-by: peter.horvath <peter.horvath@autodesk.com>

Author: peterhorvath111

src/libOpenImageIO/imagebufalgo_draw.cpp

@@ -1123,6 +1123,11 @@ ImageBufAlgo::render_text(ImageBuf& R, int x, int y, string_view text,
     // Glyph by glyph, fill in our textimg buffer
     int origx = x;
     for (auto ch : utext) {
+        // on Windows a newline is encoded as '\r\n'
+        // we simply ignore carriage return here
+        if (ch == '\r') {
+            continue;
+        }
         if (ch == '\n') {
             x = origx;
             y += fontsize;