ADD-Preserve shape properties (background color, etc.) for richttext

When loading richt text shape, read also properties who defining backgroupnd color, border color, etc.
use loadStyleFill function

Author: devX2712

src/PhpPresentation/Reader/PowerPoint2007.php

@@ -974,6 +974,12 @@ protected function loadShapeRichText(XMLReader $document, DOMElement $node, $oSl
             }
         }
 
+        $oElement = $document->getElement('p:spPr', $node);
+        if ($oElement instanceof \DOMElement) {
+            $oFill = $this->loadStyleFill($document, $oElement);
+            $oShape->setFill($oFill);
+        }
+
         if (count($oShape->getParagraphs()) > 0) {
             $oShape->setActiveParagraph(0);
         }