Enable PDF files in preview pane (#9088)

## Summary of the Pull Request
This PR enables user to preview PDF files in the Explorer preview pane
and in Outlook. 

**What is this about:**
Windows does not support out of the box experience for previewing PDF
files in the preview pane. Users need to install third-party software
like Adobe Acrobat reader. The PdfPreviewHandler module enbales the user
to preview PDF files.

**How does someone test / validate:** 
Run the installer, open Explorer and select a PDF file, enable the
preview pane. Maybe need to remove third-party PDF software.

## Quality Checklist

- [X] **Linked issue:** #3548
- [ ] **Communication:** I've discussed this with core contributors in the issue. 
- [X] **Tests:** Added/updated and all pass
- [X] **Installer:** Added/updated and all pass
- [X] **Localization:** All end user facing strings can be localized
- [ ] **Docs:** Added/ updated
- [x] **Binaries:** Any new files are added to WXS / YML
   - [ ] No new binaries
   - [x] YML for signing
   - [x] WXS for installer

src/settings-ui/Microsoft.PowerToys.Settings.UI/Strings/en-us/Resources.resw

@@ -581,6 +581,10 @@
     <value>Enable SVG (.svg) preview</value>
     <comment>Do you want this feature on / off</comment>
   </data>
+  <data name="FileExplorerPreview_ToggleSwitch_Preview_PDF.Header" xml:space="preserve">
+    <value>Enable PDF (.pdf) preview</value>
+    <comment>Do you want this feature on / off</comment>
+  </data>
   <data name="FileExplorerPreview_ToggleSwitch_SVG_Thumbnail.Header" xml:space="preserve">
     <value>Enable SVG (.svg) thumbnails</value>
     <comment>Do you want this feature on / off</comment>