Adds support for JUMBO thumbnails in the helper (#38539)

Adds a parameter to `Toolkit.ThumbnailHelper.GetThumbnail` to retrieve the largest possible icon from the file. For most use cases, the normal icon size will be good for list items and page icons. 

But for details, you'll want to use the JUMBO icons, and to retrieve them, we need to get the icon from a different API. 

As a drive-by, I also have us fetching the highest-res app icon for UWP's rather than the lowest-res icon.

Solves #38238 

Screenshots:
| before | after | 
| ------ | ----- |
| ![image](https://github.com/user-attachments/assets/8aebf163-2f71-45c5-9bee-052ef5528c58) | ![image](https://github.com/user-attachments/assets/7d7b417a-d8d0-4234-ad2b-446a4ca804ba) |
| ![image](https://github.com/user-attachments/assets/3aa21305-2d5f-40a5-a091-fbe5ca5f332c) | ![image](https://github.com/user-attachments/assets/beb5e62f-c649-4cbc-8f6e-8d2c1655cac0) |

.github/actions/spell-check/expect.txt

@@ -678,6 +678,7 @@ IGo
 iid
 Iindex
 Ijwhost
+ILD
 IMAGEHLP
 IMAGERESIZERCONTEXTMENU
 IMAGERESIZEREXT
@@ -1453,6 +1454,9 @@ SHELLDLL
 shellex
 SHELLEXECUTEINFO
 SHELLEXECUTEINFOW
+SHELLEXTENSION
+SHELLICONSIZE
+SHELLNEWVALUE
 SHFILEINFO
 SHFILEOPSTRUCT
 SHGDN
@@ -1460,6 +1464,7 @@ SHGDNF
 SHGFI
 SHGFIICON
 SHGFILARGEICON
+SHIL
 shinfo
 shlwapi
 shobjidl