[desktop] Data Manager, data import/export (#2700)

This adds a "Data Manager" dialog to the Tools menu. The Data Manager allows for the following operations:
- Open w/ system file manager
- Clear
- Export
- Import

On any of the following directories:
- Save (w/ profile selector)
- UserNAND
- SysNAND
- Mods
- Shaders

TODO for the future:
- "Cleanup" for each directory
- TitleID -> Game name--let users clean data for a specific game if applicable

Signed-off-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2700
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Lizzie <lizzie@eden-emu.dev>

src/qt_common/qt_content_util.h

@@ -6,6 +6,7 @@
 
 #include <QObject>
 #include "common/common_types.h"
+#include "frontend_common/data_manager.h"
 
 namespace QtCommon::Content {
 
@@ -46,6 +47,13 @@ void InstallKeys();
 void VerifyGameContents(const std::string &game_path);
 void VerifyInstalledContents();
 
+void ClearDataDir(FrontendCommon::DataManager::DataDir dir, const std::string &user_id = "");
+void ExportDataDir(FrontendCommon::DataManager::DataDir dir,
+                   const std::string &user_id = "",
+                   const QString &name = QStringLiteral("export"),
+                   std::function<void()> callback = {});
+void ImportDataDir(FrontendCommon::DataManager::DataDir dir, const std::string &user_id = "", std::function<void()> callback = {});
+
 // Profiles //
 void FixProfiles();
 }