removal of all getByte loads (#3153)

# Description of Changes

Please provide a summary of the changes, including:

- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: a <a>

src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java

@@ -90,7 +90,7 @@ public class CertSignController {
 
     private static void sign(
             CustomPDDocumentFactory pdfDocumentFactory,
-            byte[] input,
+            MultipartFile input,
             OutputStream output,
             CreateSignature instance,
             Boolean showSignature,
@@ -179,7 +179,7 @@ public class CertSignController {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         sign(
                 pdfDocumentFactory,
-                pdf.getBytes(),
+                pdf,
                 baos,
                 createSignature,
                 showSignature,

src/main/java/stirling/software/SPDF/controller/api/security/GetInfoOnPDF.java

@@ -126,7 +126,7 @@ public class GetInfoOnPDF {
     @Operation(summary = "Summary here", description = "desc. Input:PDF Output:JSON Type:SISO")
     public ResponseEntity<byte[]> getPdfInfo(@ModelAttribute PDFFile request) throws IOException {
         MultipartFile inputFile = request.getFileInput();
-        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile.getBytes()); ) {
+        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile); ) {
             ObjectMapper objectMapper = new ObjectMapper();
             ObjectNode jsonOutput = objectMapper.createObjectNode();