Fix: Fixed an issue where start menu pins had the wrong icon

[Lamparter]

Resolved / Related Issues

• Closes Bug: Pinning an EXE to Start menu results in displaying the wrong icon (Files app icon) in Start menu #12191

Steps used to test these changes

This PR is pretty complicated, but this is how you can test every part of it:

• The pin/unpin from start actions are now only executable if they are appropriate (you can only pin if the item is not already pinned, and you can only unpin if the item is already pinned)

  1. Opened the app
  2. Selected a single item in the file browser
  3. Observed that the 'unpin' action cannot be executed whereas the 'pin' action can
  4. Ran the 'pin' action on the file via the omnibar
  5. Observed that the 'pin' action can no longer be executed on that item whereas the 'unpin' action can
  6. Ran the 'unpin' action on the file via the omnibar
  7. Observed that the state reset and now the unpin button is greyed out again

• Pinning/unpinning is possible and works correctly when multiple files/folders are selected

• Pinning an item to the start menu now shows the item's icon in the start menu

  1. Pinned a file to the Start menu via the 'pin' action

  2. Ran the 'pin' action and accepted the dialogue

  3. Opened the Start menu

  4. Observed that the item is now pinned, and that the file thumbnail is its icon

     

• Start menu tile IDs are now fully unique

  1. Pinned a file to the Start menu via the 'pin' action
  2. Opened %localappdata%\FilesDev_ykqwq8d6ps0ag\LocalState\startmenu in File Explorer
  3. Observed that there are now thumbnail images with a GUID name (e.g. 5a346596-28e7-bf9a-1743-91335747ad8e.png) - each image name corresponds to its identical pinned start tile ID (this ensures that start tile IDs will always be the same)
  4. Observed that unpinning a start tile (using the 'unpin' action) deletes the image file

[Lamparter]

• You can no longer pin any item that is not an executable
• There is a bad framing border (might not be possible to fix)
• Clicking on tiles that link to a file shows an error in the app
  • #18740
• The app cannot process file open events (change activation handler)
• Use completely unique start menu IDs (Guid)
• It's possible to pin an item inside an archive
• Some files do not open correctly

The top zip file opens correctly, but the bottom one does not. Both open in File Explorer when they ought to open in Files (because they are zip files)

[Lamparter]

If a file icon cannot be obtained, the tile defaults to the app icon

[Josh65-2201]

You can no longer pin any item that is not an executable

Folders are meant to be allowed to pin

[Lamparter]

Yes, that checklist is for the bugs I accidentally introduced in this PR that I'm working to fix / parts of the PR that aren't finished yet