feat: implement save management features

- Added new save management functionality including listing, deleting, and backing up emulator saves.
- Introduced `EmulatorSaves` and `SaveEntry` types to manage save data structure.
- Created `saveManager.ts` to handle save file operations and directory scanning.
- Developed `SaveManagerPage` component for user interface to view and manage saves by game or emulator.
- Updated global types to include save management methods in the renderer.
- Removed obsolete `types.d.ts` and its source map.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "omniemu2",
-  "version": "0.1.3",
+  "version": "0.3.0",
   "description": "Cross-platform emulator manager, game launcher and ROM manager",
   "main": "dist/main/index.js",
   "scripts": {