Load pdf libs when needed (#1902)

* feat: only load pdf-lib when its used

* feat: only load pdfjs when its used

src/main/resources/templates/rotate-pdf.html

@@ -49,6 +49,7 @@
       </div>
       <th:block th:insert="~{fragments/footer.html :: footer}"></th:block>
     </div>
+    <script type="module" th:src="@{'/pdfjs-legacy/pdf.mjs'}"></script>
     <script>
       const angleInput = document.getElementById("angleInput");
       const fileInput = document.getElementById("fileInput-input");
@@ -58,7 +59,7 @@
         console.log("loading pdf");
 
         document.querySelector("#editSection").style.display = "";
-        
+
         const existingPreview = document.getElementById("pdf-preview");
         if (existingPreview) {
           existingPreview.remove();