feat: pdf preview in the print dialog

Related: #105 (closed)

bin/backend/controls/OutputDialog.html

@@ -34,6 +34,18 @@
                     </label>
                 </td>
             </tr>
+            <tr style="display: none">
+                <td>
+                    <label class="field-container">
+                        <span class="field-container-item" title="{{labelPDFView}}">
+                            {{labelPDFView}}
+                        </span>
+                        <span class="field-container-field">
+                            <span class="quiqqer-erp-outputDialog-pdfView"></span>
+                        </span>
+                    </label>
+                </td>
+            </tr>
             <tr style="display: none">
                 <td>
                     <label class="field-container">