Rewrite Save Data & Impl Save Data Dialog (#824)

* core: Rewrite PSF parser & add encoder

add .sfo hex pattern to /scripts

* core/fs: allow to mount path as read-only

* common: Add CString wrapper to handle native null-terminated strings

* SaveData: rewrite to implement full functionality

* mock value for SYSTEM_VER

* SavaData: backup features

* SavaData: SaveDataMemory features

* imgui Ref-counted textures

- has a background thread to decode textures

* imgui: rework gamepad navigation

* PSF: fixed psf not using enum class for PSFEntryFmt (was a standard old ugly enum)

- Add null check to CString when itself is used in a nullable field

* SaveDataDialog implementation

- Fix Mounting/Unmounting check of SaveInstance

src/core/libraries/system/msgdialog.cpp

@@ -39,11 +39,6 @@ Error PS4_SYSV_ABI sceMsgDialogGetResult(DialogResult* result) {
     if (result == nullptr) {
         return Error::ARG_NULL;
     }
-    for (const auto v : result->reserved) {
-        if (v != 0) {
-            return Error::PARAM_INVALID;
-        }
-    }
     *result = g_result;
     return Error::OK;
 }