[desktop] fix save data location, orphaned profiles finder (#2678)

Previously, if the user had their NAND in a nonstandard location,
profiles.dat would be read from the standard Eden path and thus return
effectively garbage data. What this would result in is:

- The Qt profile manager would be completely nonfunctional
- "Open Save Data Location" would put you into the completely wrong
  place
- Games would read from incorrect locations for their saves

To solve this, I made it so that profiles.dat is re-read *after*
QtConfig initializes. It's not the perfect solution, but it works.

Additionally, this adds an orphaned profiles finder:
- walks through the save folders in nand/user/save/000.../
- for each subdirectory, checks to see if profiles.dat contains a
  corresponding UUID
- If not, the profile is "orphaned". It may contain legit save data, so
  let the user decide how to handle it (famous last words)
- Empty profiles are just removed. If they really matter, they're
  instantly recreated anyways.

The orphaned profiles check runs right *after* the decryption keys
check, but before the game list ever gets populated

Signed-off-by: crueter <crueter@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2678
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

src/common/fs/fs_types.h

@@ -1,8 +1,12 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <filesystem>
 #include <functional>
 
 #include "common/common_funcs.h"