Fix tab container logic bug (#2840)

# Description of Changes

Please provide a summary of the changes, including:

Overhauled logic for tab-containers on sign page to fix compatibility
issues with new Tooltip system

Closes #(2839)

---

## Checklist

### General

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

### Documentation

- [ x] 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)
- [ x] 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)

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

### Testing (if applicable)

- [ x] 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.

src/main/resources/templates/sign.html

@@ -43,13 +43,13 @@
             </div>
             <script type="module" th:src="@{'/pdfjs-legacy/pdf.mjs'}"></script>
             <div class="tab-group show-on-file-selected">
-              <div class="tab-container" th:title="#{sign.upload}">
+              <div class="tab-container" th:title="#{sign.upload}" th:data-title="#{sign.upload}">
                 <div
                   th:replace="~{fragments/common :: fileSelector(name='image-upload', disableMultipleFiles=false, multipleInputsForSingleRequest=true, accept='image/*', inputText=#{imgPrompt})}">
                 </div>
               </div>
 
-              <div class="tab-container drawing-pad-container" th:title="#{sign.draw}">
+              <div class="tab-container drawing-pad-container" th:title="#{sign.draw}" th:data-title="#{sign.draw}">
                 <canvas id="drawing-pad-canvas"></canvas>
                 <br>
                 <button id="clear-signature" class="btn btn-outline-danger mt-2" onclick="signaturePad.clear()"
@@ -58,7 +58,7 @@
                   th:text="#{sign.add}"></button>
               </div>
 
-              <div class="tab-container" th:title="#{sign.saved}">
+              <div class="tab-container" th:title="#{sign.saved}" th:data-title="#{sign.saved}">
                 <div class="saved-signatures-section" th:if="${not #lists.isEmpty(signatures)}">
 
                   <!-- Preview Modal -->
@@ -130,7 +130,7 @@
                 </div>
               </div>
 
-              <div class="tab-container" th:title="#{sign.text}">
+              <div class="tab-container" th:title="#{sign.text}" th:data-title="#{sign.text}">
                 <label class="form-check-label" for="sigText" th:text="#{text}"></label>
                 <textarea class="form-control" id="sigText" name="sigText" rows="3"></textarea>
                 <label th:text="#{font}"></label>