Add support for cells in error when writing XLSX and ODS

When appending data to an existing sheet, it was possible to get cells in error when reading (DIV/0 for instance). When trying to write them back, `addRow` would throw because `Cell`s in error were not supported by the writers.

src/Spout/Common/Entity/Cell.php

@@ -91,6 +91,14 @@ class Cell
         return !$this->isError() ? $this->value : null;
     }
 
+    /**
+     * @return mixed
+     */
+    public function getValueEvenIfError()
+    {
+        return $this->value;
+    }
+
     /**
      * @param Style|null $style
      */

src/Spout/Writer/ODS/Manager/WorksheetManager.php

@@ -204,6 +204,11 @@ class WorksheetManager implements WorksheetManagerInterface
             $data .= ' office:value-type="float" calcext:value-type="float" office:value="' . $cell->getValue() . '">';
             $data .= '<text:p>' . $cell->getValue() . '</text:p>';
             $data .= '</table:table-cell>';
+        } elseif ($cell->isError() && is_string($cell->getValueEvenIfError())) {
+            // only writes the error value if it's a string
+            $data .= ' office:value-type="string" calcext:value-type="error" office:value="">';
+            $data .= '<text:p>' . $cell->getValueEvenIfError() . '</text:p>';
+            $data .= '</table:table-cell>';
         } elseif ($cell->isEmpty()) {
             $data .= '/>';
         } else {

src/Spout/Writer/XLSX/Manager/WorksheetManager.php

@@ -218,6 +218,9 @@ EOD;
             $cellXML .= ' t="b"><v>' . (int) ($cell->getValue()) . '</v></c>';
         } elseif ($cell->isNumeric()) {
             $cellXML .= '><v>' . $cell->getValue() . '</v></c>';
+        } elseif ($cell->isError() && is_string($cell->getValueEvenIfError())) {
+            // only writes the error value if it's a string
+            $cellXML .= ' t="e"><v>' . $cell->getValueEvenIfError() . '</v></c>';
         } elseif ($cell->isEmpty()) {
             if ($this->styleManager->shouldApplyStyleOnEmptyCell($styleId)) {
                 $cellXML .= '/>';